CONSERVATION BIOLOGY, Issue 4 2000
Jesper Dahlgaard
Two important issues are whether stress and inbreeding effects are independent as opposed to synergistic, and whether inbreeding effects are general across stresses as opposed to stress-specific. We found that inbreeding reduced resistance to acetone and desiccation in adult Drosophila melanogaster, whereas resistance to knockdown heat stress was not affected. Inbred flies, however, experienced a greater proportional decrease in productivity than outbreds following heat stress. Correlations using line means indicated that all resistance traits were uncorrelated in the inbred as well as in the outbred flies. Recessive, deleterious alleles therefore did not appear to have any general deleterious effects on stress resistance. Inbreeding within a specific environment and selection for resistant genotypes may therefore purge a population of deleterious genes specific to only one environmental stress. Resumen: Tanto la endogamia como el estrés ambiental pueden tener efectos adversos sobre la adaptabilidad afectando la conservación de especies en peligro de extinción. Dos temas importantes son determinar si los efectos del estrés y la endogamia son independientes en lugar de ser sinérgicos, y determinar si los efectos de la endogamia son generales para distintos tipos de estrés o si son específicos para un tipo determinado de estrés. Encontramos que la endogamia reduce la resistencia a la acetona y la desecación en adultos de Drosophila melanogaster, mientras que la resistencia al efecto demoledor del estrés por calor no fue afectada. Sin embargo, las moscas endogámicas experimentaron una disminución proporcionalmente mayor en la productividad que aquellas moscas sin endogamia después de experimentar un estrés por calor. Las correlaciones obtenidas usando líneas medias indicaron que las características de resistencia no estuvieron correlacionadas ni en moscas con endogamia, ni en moscas sin ella. Aparentemente los alelos nocivos recesivos no tuvieron ningún efecto nocivo general en la resistencia al estrés. La endogamia dentro de un ambiente específico y la selección por genotipos resistentes podrían, por lo tanto, eliminar una población de genes nocivos específicos a un solo estrés ambiental. [source]

The chemotaxis defect of Shwachman-Diamond Syndrome leukocytes

CYTOSKELETON, Issue 3 2004
Vesna Stepanovic
Abstract Shwachman-Diamond Syndrome (SDS) is a rare autosomal recessive, multisystem disorder presenting in childhood with intermittent neutropenia and pancreatic insufficiency. It is characterized by recurrent infections independent of neutropenia, suggesting a functional neutrophil defect. While mutations at a single gene locus (SBDS) appear to be responsible for SDS in a majority of patients, the function of that gene and a specific defect in SDS neutrophil behavior have not been elucidated. Therefore, employing 2D and 3D computer-assisted motion analysis systems, we have analyzed the basic motile behavior and chemotactic responsiveness of individual polymorphonuclear leukocytes (PMNs) of 14 clinically diagnosed SDS patients. It is demonstrated that the basic motile behavior of SDS PMNs is normal in the absence of chemoattractant, that SDS PMNs respond normally to increasing and decreasing temporal gradients of the chemoattractant fMLP, and that SDS PMNs exhibit a normal chemokinetic response to a spatial gradient of fMLP. fMLP receptors were also distributed uniformly through the plasma membrane of SDS PMNs as in control PMNs. SDS PMNs, however, were incapable of orienting in and chemotaxing up a spatial gradient of fMLP. This unique defect in orientation was manifested by the PMNs of every SDS patient tested. The PMNs of an SDS patient who had received an allogenic hematopoietic stem cell transplant, as well as PMNs from a cystic fibrosis patient, oriented normally. These results suggest that the defect in SDS PMNs is in a specific pathway emanating from the fMLP receptor that is involved exclusively in regulating orientation in response to a spatial gradient of fMLP. This pathway must function in parallel with additional pathways, intact in SDS patients, that emanate from the fMLP receptor and regulate responses to temporal rather than spatial changes in receptor occupancy. Cell Motil. Cytoskeleton 57:158,174, 2004. © 2004 Wiley-Liss, Inc. [source]

Aetiology in severe and mild mental retardation: a population-based study of Norwegian children

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 2 2000
Petter Strømme MD PhD
The aetiology of mental retardation (MR) was studied in a population-based series of Norwegian children derived from 30 037 children born between 1980 and 1985. The study included 178 children, 79 with severe MR (SMR) (IQ<50) and 99 with mild MR (MMR) (IQ 50 to 70). Aetiology was divided into two main groups: biopathological and unspecified. The biopathological group comprised 96% of SMR and 68% of MMR, and was subdivided into prenatal (70% and 51%), perinatal (4% and 5%), and postnatal damage (5% and 1%), and a group of undetermined timing of the damaging event (18% and 11%). Single-gene disorders accounted for 15 of the 63 children with genetic disorders, including X-linked recessive in six. During the course of the study, at least 27 (15%) children had their aetiological diagnosis revised. Gestational age <32 weeks, birthweight <1500g, and Apgar scores 0 to 2 at 1 and 5 minutes implied a significantly increased risk of MR, but contributed to only 4% of the children in the study. Decreased birthweight (1500 to 2499 g) and Apgar scores 3 to 6 at 1 and 5 minutes showed increased probability of MR. Despite extensive investigations, 4% of SMR and 32% of MMR were not identified with any biological markers and were considered as unspecified MR, several most probably representing the lower end of the normal IQ distribution in the population. [source]

Autosomal Dominant Inheritance of Centrotemporal Sharp Waves in Rolandic Epilepsy Families

EPILEPSIA, Issue 12 2007
Bhavna Bali
Summary Purpose: Centrotemporal sharp (CTS) waves, the electroencephalogram (EEG) hallmark of rolandic epilepsy, are found in approximately 4% of the childhood population. The inheritance of CTS is presumed autosomal dominant but this is controversial. Previous studies have varied considerably in methodology, especially in the control of bias and confounding. We aimed to test the hypothesis of autosomal dominant inheritance of CTS in a well-designed family segregation analysis study. Methods: Probands with rolandic epilepsy were collected through unambiguous single ascertainment. Siblings in the age range 4,16 years underwent sleep-deprived EEG; observations from those who remained awake were omitted. CTS were rated as present or absent by two independent observers blinded to the study hypothesis and subject identities. We computed the segregation ratio of CTS, corrected for ascertainment. We tested the segregation ratio estimate for consistency with dominant and recessive modes of inheritance, and compared the observed sex ratio of those affected with CTS for consistency with sex linkage. Results: Thirty siblings from 23 families underwent EEG examination. Twenty-three showed evidence of sleep in their EEG recordings. Eleven of 23 recordings demonstrated CTS, yielding a corrected segregation ratio of 0.48 (95% CI: 0.27,0.69). The male to female ratio of CTS affectedness was approximately equal. Conclusions: The segregation ratio of CTS in rolandic epilepsy families is consistent with a highly penetrant autosomal dominant inheritance, with equal sex ratio. Autosomal recessive and X-linked inheritance are rejected. The CTS locus might act in combination with one or more loci to produce the phenotype of rolandic epilepsy. [source]

Autosomal Recessive Idiopathic Epilepsy in an Inbred Family from Turkey: Identification of a Putative Locus on Chromosome 9q32-33

EPILEPSIA, Issue 5 2004
Betül Baykan
Summary: Purpose: The study describes the clinical features of an inbred family from Turkey with three members affected by seizures and tests possible autosomal recessive (AR) inheritance by means of linkage analysis. Methods: Personal and family history was obtained from each subject, and general physical, neurologic, and EEG examinations were performed. A set of 382 fluorescence-labeled markers was used for the initial genome-wide search. A further set of 83 markers was used to map the locus precisely and to exclude the remaining genome. Results: Twelve individuals from three generations were examined. Two subjects were affected by idiopathic epilepsy, whereas, their brother experienced a single unprovoked generalized seizure. Two siblings affected by idiopathic epilepsy and their unaffected sister showed a photoparoxysmal response to photic stimulation. Nine family members reported migraine. The genome-wide search led to the identification of a unique homozygous, 15.1-cM region shared by subjects with seizures on chromosome 9q32-33 and providing a lod score of 2.9. This locus, however, was not associated with migraine in this pedigree. Conclusions: The study suggests that idiopathic epileptic traits with AR inheritance might be underestimated in the general population and that inbred pedigrees may represent powerful tools for the identification of AR genes. [source]

Phenotypic and genetic analysis of the cerebellar mutant tmgc26, a new ENU-induced ROR-alpha allele

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2010
Douglas J. Swanson
Abstract ROR-alpha is an orphan nuclear receptor, inactivation of which cell-autonomously blocks differentiation of cerebellar Purkinje cells with a secondary loss of granule neurons. As part of our ENU mutagenesis screen we isolated the recessive tmgc26 mouse mutant, characterized by early-onset progressive ataxia, cerebellar degeneration and juvenile lethality. Detailed analysis of the tmgc26,/, cerebella revealed Purkinje cell and granule cell abnormalities, and defects in molecular layer interneurons and radial glia. Chimera studies suggested a cell-autonomous effect of the tmgc26 mutation in Purkinje cells and molecular layer interneurons, and a non-cell-autonomous effect in granule cells. The mutation was mapped to a 13-Mb interval on chromosome 9, a region that contains the ROR-alpha gene. Sequencing of genomic DNA revealed a T-to-A transition in exon 5 of the ROR-alpha gene, resulting in a nonsense mutation C257X and severe truncation of the ROR-alpha protein. Together, our data identify new roles for ROR-alpha in molecular layer interneurons and radial glia development and suggest tmgc26 as a novel ROR-alpha allele that may be used to further delineate the molecular mechanisms of ROR-alpha action. [source]

An optimal dose-effect mode trend test for SNP genotype tables

GENETIC EPIDEMIOLOGY, Issue 2 2009
Ryo Yamada
Abstract The genome-wide association studies have improved our understanding of the genetic basis of many complex traits. Two-by-three contingency tables are tested in these studies. The trend test for the additive mode is most often used, which is the test of 1 degree of freedom (df=1) and other tests, such as the genotype test (,2 (df=2)) and the ,2 (df=1) tests for the dominant and recessive modes are also used to increase the power for markers in the non-additive modes. However, any one of them or combination of them is not perfect. We describe the relations among the ,2 (df=2) test and ,2 (df=1) tests for the dominant and recessive modes and the trend test for the additive mode and propose a new statistic based on their relations that tests the hypothesis that the disease-susceptible allele has a dose-effect somewhere between the recessive and dominant modes, which corresponds to the optimal dose-effect for the observed data. Genet. Epidemiol. 2008. © 2008 Wiley-Liss, Inc. [source]

Insight into molecular changes of the FIX protein in a series of Italian patients with haemophilia B

HAEMOPHILIA, Issue 3 2006
M. P. BICOCCHI
Summary., Deficiency or dysfunction of factor IX FIX leads to haemophilia B (HB), an X-linked, recessive, bleeding disorder. On a molecular basis, HB is due to a heterogeneous spectrum of mutations spread throughout the F9 gene. In several instances, a cause-effect relation has been elucidated, in others predicted possibilities have been offered by crystallography inspection and by software-constructed models of the protein. The aim of this study was to contribute to the understanding of HB molecular pathology. The F9 missense mutations we identified in 21 unrelated Italian HB patients by direct sequencing of the whole F9 coding regions were inspected for the causative effect they provoked on the ensuing transcript, and on the protein structure. Each alteration was studied in order to: (i) characterize the defect on the basis of the nature of the mutation; (ii) identify the predicted defect that is induced in the gene and (iii) speculate about the potential, detrimental effects which upset the protein functionality through an idealized FIX model. The resulting data may further contribute to the comprehension of the mechanisms underlying the disease. [source]

Mutations of the CEP290 gene encoding a centrosomal protein cause Meckel-Gruber syndrome,

HUMAN MUTATION, Issue 1 2008
Valeska Frank
Abstract Meckel-Gruber syndrome (MKS) is an autosomal recessive, lethal multisystemic disorder characterized by meningooccipital encephalocele, cystic kidney dysplasia, hepatobiliary ductal plate malformation, and postaxial polydactyly. Recently, genes for MKS1 and MKS3 were identified, putting MKS on the list of ciliary disorders (ciliopathies). By positional cloning in a distantly related multiplex family, we mapped a novel locus for MKS to a 3-Mb interval on 12q21. Sequencing of the CEP290 gene located in the minimal critical region showed a homozygous 1-bp deletion supposed to lead to loss of function of the encoded centrosomal protein CEP290/nephrocystin-6. CEP290 is thought to be involved in chromosome segregation and localizes to cilia, centrosomes, and the nucleus. Subsequent analysis of another consanguineous multiplex family revealed homozygous haplotypes and the same frameshift mutation. Our findings add to the increasing body of evidence that ciliopathies can cause a broad spectrum of disease phenotypes, and pleiotropic effects of CEP290 mutations range from single organ involvement with isolated Leber congenital amaurosis to Joubert syndrome and lethal early embryonic multisystemic malformations in Meckel-Gruber syndrome. We compiled clinical and genetic data of all patients with CEP290 mutations described so far. No clear-cut genotype,phenotype correlations were apparent as almost all mutations are nonsense, frameshift, or splice-site changes and scattered throughout the gene irrespective of the patients' phenotypes. Conclusively, other factors than the type and location of CEP290 mutations may underlie phenotypic variability. Hum Mutat 29(1), 45,52, 2008. © 2007 Wiley-Liss, Inc. [source]

Low frequency of AXIN2 mutations and high frequency of MUTYH mutations in patients with multiple polyposis,,

HUMAN MUTATION, Issue 10 2006
Sophie Lejeune
Abstract Familial adenomatous polyposis has been linked to germline mutations in the APC tumor suppressor gene. However, a number of patients with familial adenomatous polyposis (with either classical or attenuated phenotype) have no APC mutation. Recently, germline mutations in the Wnt pathway component gene AXIN2 have been associated with tooth agenesis-colorectal cancer syndrome. Moreover, biallelic mutations in the base excision repair gene MUTYH have been associated with polyposis and early-onset colorectal cancer. The aim of this study was to further assess the contribution of AXIN2 and MUTYH to hereditary colorectal cancer susceptibility. AXIN2 and MUTYH genes were screened for germline mutations by PCR and direct sequencing in 39 unrelated patients with multiple adenomas or colorectal cancer without evidence of APC mutation nor mismatch repair defect. Two novel AXIN2 variants were detected in one patient with multiple adenomas, but no clearly pathogenic mutation. In contrast, nine different MUTYH mutations were detected in eight patients, including four novel mutations. Biallelic MUTYH mutations were only found in patients with multiple adenomatous polyposis (7 out of 22 (32%)). Interestingly, five MUTYH mutation carriers had a family history consistent with dominant inheritance. Moreover, one patient with biallelic MUTYH mutations presented with multiple adenomas and severe tooth agenesis. Therefore, germline mutations are rare in AXIN2 but frequent in MUTYH in patients with multiple adenomas. Our data suggest that genetic testing of MUTYH may be of interest in patients with pedigrees apparently compatible with autosomal recessive as well as dominant inheritance. © 2006 Wiley-Liss, Inc. [source]

D90A- SOD1 mediated amyotrophic lateral sclerosis: A single founder for all cases with evidence for a Cis -acting disease modifier in the recessive haplotype,,

HUMAN MUTATION, Issue 6 2002
Matthew J. Parton
Abstract More than 100 different heterozygous mutations in copper/zinc superoxide dismutase (SOD1) have been found in patients with amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease. Uniquely, D90A- SOD1 has been identified in recessive, dominant and apparently sporadic pedigrees. The phenotype of homozygotes is stereotyped with an extended survival, whereas that of affected heterozygotes varies. The frequency of D90A- SOD1 is 50 times higher in Scandinavia (2.5%) than elsewhere, though ALS prevalence is not raised there. Our earlier study indicated separate founders for recessive and dominant/sporadic ALS and we proposed a disease-modifying factor linked to the recessive mutation. Here we have doubled our sample set and employed novel markers to characterise the mutation's origin and localise any modifying factor. Linkage disequilibrium analysis indicates that D90A homozygotes and heterozygotes share a rare haplotype and are all descended from a single ancient founder (alpha 0.974) c.895 generations ago. Homozygotes arose subsequently only c.63 generations ago (alpha 0.878). Recombination has reduced the region shared by recessive kindreds to 97-265 kb around SOD1, excluding all neighbouring genes. We propose that a cis -acting regulatory polymorphism has arisen close to D90A- SOD1 in the recessive founder, which decreases ALS susceptibility in heterozygotes and slows disease progression. © 2002 Wiley-Liss, Inc. [source]

Differential control of apoptosis by DJ-1 in prostate benign and cancer cells

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2004
Yaacov Hod
Abstract DJ-1 is a conserved protein reported to be involved in diverse cellular processes ranging from cellular transformation, control of protein,RNA interaction, oxidative stress response to control of male infertility, among several others. Mutations in the human gene have been shown to be associated with an autosomal recessive, early onset Parkinson's disease (PARK7). The present study examines the control of DJ-1 expression in prostatic benign hyperplasia (BPH-1) and cancer (PC-3) cell lines in which DJ-1 abundance differs significantly. We show that while BPH-1 cells exhibit low basal level of DJ-1 expression, stress-inducing agents such as H2O2 and mitomycin C markedly increase the intracellular level of the polypeptide. In contrast, DJ-1 expression is relatively high in PC-3 cells, and incubation with the same cytotoxic drugs does not modulate further the level of the polypeptide. In correlation with the expression of DJ-1, both cytotoxic agents activate the apoptotic pathway in the prostatic benign cells but not in PC-3 cells, which are resistant to their action. We further demonstrate that incubation of BPH-1 cells with TNF-related-apoptosis-inducing-ligand/Apo-2L (TRAIL) also enhances DJ-1 expression and that TRAIL and H2O2 act additively to stimulate DJ-1 accumulation but synergistically in the activation of the apoptotic pathway. Time-course analysis of DJ-1 stimulation shows that while DJ-1 level increases without significant lag in TRAIL-treated cells, there is a delay in H2O2 -treated cells, and that the increase in DJ-1 abundance precedes the activation of apoptosis. Unexpectedly, over-expression of DJ-1 de-sensitizes BPH-1 cells to the action of apoptotic-inducing agents. However, RNA-interference-mediated silencing of DJ-1 expression results in sensitization of PC-3 cells to TRAIL action. These results are consistent with a model in which DJ-1 is involved in the control of cell death in prostate cell lines. DJ-1 appears to play a differential role between cells expressing a low but inducible level of DJ-1 (e.g., BPH-1 cells) and those expressing a high but constitutive level of the polypeptide (e.g., PC-3 cells). © 2004 Wiley-Liss, Inc. [source]

Acellular dermal matrix allograft used to gain attached gingiva in a case of epidermolysis bullosa

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2003
Eralp Buduneli
Abstract Background: Epidermolysis bullosa (EB) is an acquired disease or inherited as either autosomal dominant or recessive with an incidence of 1/50,000. The prominent clinical characteristic of the disease is the development of bullae or vesicles in mucosa or skin in response to minor trauma. Aim: A female patient with a dystrophic type of EB had been put in a maintenance regimen after completion of the initial phase of periodontal therapy and followed for 7 years. The purpose of this report is to document acellular dermal matrix allograft application to increase the width of the attached gingiva in this patient experiencing difficulty in chewing and performing plaque control due to the dramatic loss of attached gingiva after 7 years of supportive periodontal therapy. Methods: Under local anaesthesia and antibiotic coverage, the acellular dermal matrix allograft was applied in the anterior region of the upper jaw in order to increase the width of attached gingiva, thereby improving patient comfort. Results: The healing was uneventful and a significant gain in attached gingiva dimensions was observed 9 months after the periodontal surgery. The procedure avoided a second surgical site, provided satisfactory results from an aesthetic point of view, and improved patient comfort. Conclusion: Acellular dermal matrix allograft may be regarded as an alternative in the treatment of EB cases to increase the width of attached gingiva and facilitate maintenance of the dentition. Zusammenfassung Hintergrund: Die Epidermolysis bullosa (EB) ist eine erworbene oder eine autosomal dominant oder rezessiv vererbte Krankheit mit einer Incidenz von 1:50,000. Die hervorstechenden klinischen Symptome dieser Erkrankung sind die Entwicklung von Blasen oder Vesikeln in der Mukosa oder in der Haut auf geringste Traumen. Ziel: Eine Frau mit dem dystrophischen Typ von EB wurde in der Erhaltungsphase seit 7 Jahren geführt, nachdem die initiale Phase der parodontalen Therapie beendet worden war. Der Zweck dieser Studie ist die Dokumentation der Applikation eines azellulären Hautmatrixtransplantats für die Verbreiterung der fest angewachsenen Gingiva bei dieser Patientin, die nach 7 Jahren der erhaltenden parodontalen Therapie Probleme beim Kauen und bei der Durchführung der Plaquekontrolle durch einen starken Verlust an fest angewachsener Gingiva hatte. Methoden: Unter lokaler Anästhesie und antibiotischer Abschirmung wurde das azelluläre Hautmatrixtransplantat in die anteriore Region des Oberkiefers appliziert, um die Breite der fest angewachsenen Gingiva zu vergrößern und so das Befinden der Patientin zu verbessern. Ergebnisse: Die Heilung war komplikationslos, und ein signifikanter Gewinn an fest angewachsener Gingiva 9 Monate nach der parodontalen Operation wurde beobachtet. Die Methode vermied eine zweite chirurgische Region, erbrachte zufriedenstellende Ergebnisse aus ästhetischer Sicht und verbesserte das Befinden der Patientin. Schlussfolgerung: Das azelluläre Hautmatrixtransplantat kann als eine Alternative in der Behandlung von EB betrachtet werden, um die Breite der fest angewachsenen Gingiva zu vergrößern und zur Möglichkeit der Erhaltung der Dentition beizutragen. Résumé La bullose épidermolysie (EB) est une maladie contractée ou héritée qui peut être aussi bien autosomale dominante que récessive avec une fréquence de 1/50,000. La caractéristique clinique importante de la maladie est le développement de bulles ou de vésicules au niveau de la muqueuse ou de la peau comme réponse à un traumatisme mineur. Une femme avec un type dystrophique de EB a été placée dans un régime de maintenance après la fin de la phase initiale du traitement parodontal et suivie durant sept années. Le but de ce rapport est de documenter le placement d'un allographe de la matrice dermique acellulaire visant à augmenter la largeur de la gencive attachée chez cette patiente qui avait des problèmes aux niveaux masticatoire et du contrôle de la plaque dentaire vu la perte dramatique de la gencive attachée après sept années de maintenance parodontale. Sous anesthésie locale et sous couverture antibiotique, l'allographe de la matrice dermique acellulaire a été placé dans la région antérieure de la mâchoire supérieure pour augmenter la largeur de la gencive attachée afin d'améliorer le confort de la patiente. La guérison s'est déroulée sans problème et un gain significatif de gencive attachée a été observé neuf mois après la chirurgie parodontale. Ce processus chirurgical élimine la nécessité d'avoir un site donneur, apporte des résultats satisfaisants du point de vue esthétique et améliore le confort du patient. L'allographe de la matrice dermique acellulaire peut donc être considéré comme une alternative dans le traitement des cas de EB afin d'augmenter la largeur de la gencive attachée et faciliter le maintien de la dentition. [source]

Inbreeding depression by recessive deleterious genes affecting female fecundity of a haplo-diploid mite

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2000
Saito
The effect of inbreeding on haplo-diploid organisms has been regarded as very low, because deleterious recessive genes on hemizygous (haploid) males were immediately purged generation by generation. However, we determined such recessive genes to decrease female fecundity in a population of Schizotetranychus miscanthi Saito which is known in the Acari as a subsocial species with haplo-diploidy. In mother,son inbreeding experiments, there was no depression in egg hatchability nor in the larval survival of progeny over four generations. There was, on the other hand, significant inbreeding depression in the fecundity with increasing f -value. Crosses between two lineages, one having deleterious effects on the fecundity and the other having no such effects, established during the inbreeding, revealed heterosis, and backcrosses showed that the depression was caused by deleterious recessive(s). These results strongly suggest the existence of some deleterious genes governing only the traits of adult females in wild populations of haplo-diploid organisms. [source]

Pathogenesis of familial Parkinson's disease: new insights based on monogenic forms of Parkinson's disease

JOURNAL OF NEUROCHEMISTRY, Issue 5 2009
Taku Hatano
Abstract Parkinson's disease (PD) is one of the most common movement disorders caused by the loss of dopaminergic neuronal cells. The molecular mechanisms underlying neuronal degeneration in PD remain unknown; however, it is now clear that genetic factors contribute to the pathogenesis of this disease. Approximately, 5% of patients with clinical features of PD have clear familial etiology, which show a classical recessive or dominant Mendelian mode of inheritance. Over the decade, more than 15 loci and 11 causative genes have been identified so far and many studies shed light on their implication in not only monogenic but also sporadic form of PD. Recent studies revealed that PD-associated genes play important roles in cellular functions, such as mitochondrial functions, ubiquitin-proteasomal system, autophagy-lysosomal pathway and membrane trafficking. Furthermore, the proteins encoded by PD-associated genes can interact with each other and such gene products may share a common pathway that leads to nigral degeneration. However, their precise roles in the disease and their normal functions remain poorly understood. In this study, we review recent progress in knowledge about the genes associated with familial PD. [source]

The mediterranean fever gene modifies the progression of disability in non-Ashkenazi Jewish multiple sclerosis patients

JOURNAL OF NEUROCHEMISTRY, Issue 2002
Y. Shinar
MS is an autoimmune, CNS demyelinating disease manifested in most patients with progressive disability. The progression rate varies between patients and may depend on modifier, immune related genes. The Mediterranean fever gene, expressed in peripheral blood leukocytes, is responsible for familial Mediterranean fever (FMF), a recessive, periodic autoinflammatory disease prevalent in Semitic populations, and less penetrant in Ashkenazi Jews. We related common, FMF associated MEFV mutations to the progression of disability in Jewish, relapsing remitting (RR) MS patients. The mutations 148Q, 694V, 695R and 726A were identified by enzymatic restriction of PCR-amplified MEFV DNA. The progression to statuses 3 and 6 of the expanded disability status scale (EDSS) was analyzed on survival plots. 35% of 48 non-Ashkenazi patients had one MEFV mutation. Compared to non-carriers (n = 31) the heterozygous cohort (n = 17) represented with an increased fraction reaching both EDSS statuses (p < 0.05), and with a shorter median time to reach both EDSS =,3 (2 years in carriers vs. 10 years in non-carriers, p < 0.01) and EDSS =,6 (6 vs. 23 years, respectively, p < 0.005). 17% of 71 Ashkenazi patients had one MEFV mutation. There was no significant difference in the fraction of disabled or in the progression of disability between Ashkenazi carrier patients and non-carriers. The susceptibility of the non-Ashkenazi group attributed, in part, to the detrimental non-Ashkenazi 694V mutation. The results suggest phenotypic expression of one mutated MEFV gene in non-ashkenazi patients, pertinent to the pathogenesis of disability. Acknowledgements:, Granted by the Israeli Ministry of Science (#6279). [source]

Bartter's Syndrome in Pregnancy: A Case Report and Review

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2000
Dr. Ivy C. F. Li
Abstract Bartter's syndrome is a rare renal tubular disorder, involving juxtaglomerular cells hyperplasia, characterized by normotensive hyper-reninism and secondary hyperaldosteronism, marked renal loss of potassium and profound hypokalaemia. Both clinical and biochemical features are heterogeneous, ranging from the incidental finding in an asymptomatic patient to marked clinical features of hypokalaemia. Inheritance is likely to be an autosomal recessive. We present a case of Bartter's syndrome complicating pregnancy in a Chinese woman. We documented an increasing demand for potassium supplement during pregnancy which stabilized by mid-trimester. The absence of pregnancy complications such as polyhydramnios indicated that the fetus was unlikely to be affected by the condition. [source]

Genotype,phenotype correlation in some autosomal recessive hereditary spastic paraplegias

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 2 2004
F Manganelli
Hereditary spastic paraplegias (HSPs) are a group of clinically and genetically inherited disorders. Spastic paraparesis (SP), the main clinical feature of all HSPs can occur in relative isolation in the "pure" form or in combination with other neurological deficits in "complicated" forms. Autosomal dominant, autosomal recessive (AR) and X-linked recessive inheritance pattern of HSPs have been reported. At present, among AR-HSPs, three genes, paraplegin (SPG7), spartin (SPG20 , Troyer syndrome) and maspardin (SPG21) have been identified and six genetic loci have been mapped (SPG5, SPG11, SPG14, SPG15, SPG24, SPG25). We have evaluated 11 patients belonging to six AR-HSP families genetically identified as SPG5, SPG7, SPG11 and SPG15. In all patients electromyography, nerve conduction velocity studies, visual (VEPs), somatosensory (SSEPs), brainstem auditory (BAEPs) and magnetic motor (MMEPs) evoked potentials were performed. All 4 SPG5 patients, affected by a pure form of SP, showed abnormalities of both MMEPs and SSEPs, and two of them also VEP alterations. In the two SPG7 patients with complicated SP, MMEP abnormalities only were discovered. Among the three SPG11 patients affected by SP, complicated by mental retardation and thin corpus callosum, electrophysiological studies revealed MMEP abnormalities and signs of motor neuropathy in one of them. Finally, in the SPG15 family, presenting with SP associated with mental retardation and neurosensorial deafness, MMEP and BAEP alterations were found. [source]

Transcription activator-like type III effector AvrXa27 depends on OsTFIIA,5 for the activation of Xa27 transcription in rice that triggers disease resistance to Xanthomonas oryzae pv. oryzae

MOLECULAR PLANT PATHOLOGY, Issue 6 2009
KEYU GU
SUMMARY The transcription activator-like (TAL) type III effector AvrXa27 from Xanthomonas oryzae pv. oryzae (Xoo) strain PXO99A activates the transcription of the host resistance gene Xa27, which results in disease resistance to bacterial blight (BB) in rice. In this study, we show that AvrXa27-activated Xa27 transcription requires host general transcription factor OsTFIIA,5. The V39E substitution in OsTFIIA,5, encoded by the recessive resistance gene xa5 in rice, greatly attenuates this activation in xa5 and Xa27 double homozygotes on inoculation with Xa27 -incompatible strains. The xa5 gene also causes attenuation in the induction of Xa27 by AvrXa27 expressed in rice. The xa5 -mediated attenuation of Xa27 -mediated resistance to PXO99A is recessive. Intriguingly, xa5 -mediated resistance to xa5 -incompatible strains is also down-regulated in the xa5 and Xa27 double homozygotes. In addition, AvrXa27 expressed in planta shows weak virulence activity in the xa5 genetic background and causes enhanced susceptibility of the plants to BB inoculation. The results suggest that TAL effectors target host general transcription factors to directly manipulate the host transcriptional machinery for virulence and/or avirulence. The identification of xa5 -mediated attenuation of Xa27 -mediated resistance to Xoo provides a guideline for breeding resistance to BB when pyramiding xa5 with other resistance genes. [source]

Frequency analysis and clinical characterization of different types of spinocerebellar ataxia in Serbian patients

MOVEMENT DISORDERS, Issue 2 2006
a T. Draga
Abstract The relative frequencies of different spinocerebellar ataxias (SCAs) vary widely among different ethnic groups, presumably due to a founder effect. We investigated the relative prevalence of SCA1,3, 6,8, 12, 17; dentate,rubro,pallidoluysian atrophy; and Friedreich's ataxia (FRDA) in Serbian patients with adult-onset (>20 years of age) hereditary and sporadic SCAs, and compared clinical features of patients with genetically confirmed SCAs. A total of 108 patients from 54 families (38 apparently dominant [ADCA] and 16 apparently recessive) with adult-onset hereditary ataxia and 75 apparently sporadic patients were assessed. Of 38 families with ADCA, 13 (34%) were positive for an expansion in an SCA1 and 5 families (13%) for an expansion in an SCA2 allele. In 20 families (53%), no expansions have been identified in any of the analyzed genes. Gaze palsy, spasticity, and hyperreflexia were significantly more common in SCA1, whereas slow saccades, hypotonia, hyporeflexia, and dystonia prevailed in SCA2 patients. Among the 16 families with an apparently recessive mode of ataxia inheritance, 4 (25%) were identified as having the FRDA mutation. Ataxia-causing mutations were identified in 8 (10.6%) of patients with apparently sporadic adult-onset ataxia. © 2005 Movement Disorder Society [source]

Kufor Rakeb Disease: Autosomal recessive, levodopa-responsive parkinsonism with pyramidal degeneration, supranuclear gaze palsy, and dementia

MOVEMENT DISORDERS, Issue 10 2005
David R. Williams MBBS, FRACP
Abstract Kufor Rakeb disease is an autosomal recessive disorder characterized by subacute, juvenile-onset, levodopa-responsive parkinsonism, pyramidal signs, dementia, and a supranuclear gaze palsy. It was originally described more than a decade ago, and linkage analysis identified a locus on chromosome 1p36 that was previously assigned PARK9. We have further characterized the clinical picture and specifically re-assessed the response to levodopa in the original family, in the northern highlands of Jordan. In the 4 surviving patients, there has been a narrowing of the therapeutic window for levodopa with the emergence of peak-dose dyskinesias with increased spasticity and cognitive decline. Several new features were identified, including facial-faucial-finger mini-myoclonus, visual hallucinations, and oculogyric dystonic spasms. © 2005 Movement Disorder Society [source]

Haemolytic uraemic syndrome: An overview (Review Article)

NEPHROLOGY, Issue 3 2006
IRADJ AMIRLAK
SUMMARY: Haemolytic uraemic syndrome (HUS) is the most common cause of acute renal failure in children. The syndrome is defined by triad of microangiopathic haemolytic anaemia, thrombocytopenia and acute renal failure (ARF). Incomplete HUS is ARF with either haemolytic anaemia or thrombocytopenia. HUS is classified into two subgroups. Typical HUS usually occurs after a prodrome of diarrhoea (D+HUS), and atypical (sporadic) HUS (aHUS), which is not associated with diarrhoea (D,HUS). The majority of D+HUS worldwide is caused by Shiga toxin-producing Esherichia coli (STEC), type O157:H7, transmitted to humans via different vehicles. Currently there are no specific therapies preventing or ameliorating the disease course. Although there are new therapeutic modalities in the horizon for D+HUS, present recommended therapy is merely symptomatic. Parenteral volume expansion may counteract the effect of thrombotic process before development of HUS and attenuate renal injury. Use of antibiotics, antimotility agents, narcotics and non-steroidal anti-inflammatory drugs should be avoided during the acute phase. Prevention is best done by preventing primary STEC infection. Underlying aetiology in many cases of aHUS is unknown. A significant number may result from underlying infectious diseases, namely Streptococcus pneumoniae and human immunedeficiency virus. Variety of genetic forms include HUS due to deficiencies of factor H, membrane cofactor protein, Von Willebrand factor-cleaving protease (ADAMTS 13) and intracellular defect in vitamin B12 metabolism. There are cases of aHUS with autosomal recessive and dominant modes of inheritance. Drug-induced aHUS in post-transplantation is due to calcineurin-inhibitors. Systemic lupus erythematosus and catastrophic antiphospholipid syndrome may also present with aHUS. Therapy is directed mainly towards underlying cause. [source]

Investigating the etiology of multiple tooth agenesis in three sisters with severe oligodontia

ORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 1 2008
S Swinnen
Structured Abstract Authors,,, Swinnen S, Bailleul-Forestier I, Arte S, Nieminen P, Devriendt K, Carels C Objectives,,, To describe the dentofacial phenotypes of three sisters with severe non-syndromic oligodontia, to report on the mutation analysis in three genes, previously shown to cause various phenotypes of non-syndromic oligodontia and in two other suspected genes. Based on the phenotypes in the pedigree of this family, the different possible patterns of transmission are discussed. Methods,,, Anamnestic data and a panoramic radiograph were taken to study the phenotype of the three sisters and their first-degree relatives. Blood samples were also taken to obtain their karyotypes and DNA samples. Mutational screening was performed for the MSX1, PAX9, AXIN2, DLX1 and DLX2 genes. Results,,, The probands' pedigree showed evidence for a recessive or multifactorial inheritance pattern. Normal chromosomal karyotypes were found and , despite the severe oligodontia present in all three sisters , no mutation appeared to be present in the five genes studied so far in these patients. Conclusions,,, In the three sisters reported, their common oligodontia phenotype is not caused by mutations in the coding regions of MSX1, PAX9, AXIN2, DLX1 or DLX2 genes, but genetic factors most probably play a role as all three sisters were affected. Environmental and epigenetic factors as well as genes regulating odontogenesis need further in vivo and in vitro investigation to explain the phenotypic heterogeneity and to increase our understanding of the odontogenic processes. [source]

Autosomal Dominant Epidermodysplasia Verruciformis Lacking a Known EVER1 or EVER2 Mutation

PEDIATRIC DERMATOLOGY, Issue 3 2009
David F. McDermott M.D.
Epidermodysplasia verruciformis is a genetically heterogeneous disease, and autosomal recessive and X-linked inheritance patterns have been reported. Nonsense mutations in the genes EVER1 and EVER2 have been identified in over 75% of cases. We present epidermodysplasia verruciformis in a father and a son with typical histologic and clinical findings that occur in the absence of mutations in EVER1 or EVER2. Epidermodysplasia verruciformis in this father/son pair in a nonconsanguinous pedigree is consistent with autosomal dominant inheritance. This is the first report of autosomal dominant transmission of epidermodysplasia verruciformis, providing further evidence of the genetic heterogeneity of epidermodysplasia verruciformis. [source]

Genetics of spinosad resistance in a multi-resistant field-selected population of Plutella xylostella

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2004
Ali H Sayyed
Abstract Resistance to the bacteria-derived insecticides spinosad (Conserve), abamectin (Vertimec), Bacillus thuringiensis var kurstaki (Btk) (Dipel), B thuringiensis var aizawai (Bta) (Xentari), B thuringiensis crystal endotoxins Cry1Ac and Cry1Ca, and to the synthetic insecticide fipronil was estimated in a freshly-collected field population (CH1 strain) of Plutella xylostella (L) from the Cameron Highlands, Malaysia. Laboratory bioassays at G1 indicated significant levels of resistance to spinosad, abamectin, Cry1Ac, Btk, Cry1Ca, fipronil and Bta when compared with a laboratory insecticide-susceptible population. Logit regression analysis of F1 reciprocal crosses indicated that resistance to spinosad in the CH1 population was inherited as a co-dominant trait. At the highest dose of spinosad tested, resistance was close to completely recessive, while at the lowest dose it was incompletely dominant. A direct test of monogenic inheritance based on a back-cross of F1 progeny with CH1 suggested that resistance to spinosad was controlled by a single locus. Copyright © 2004 Society of Chemical Industry [source]

Cross-resistance and inheritance of resistance to Bacillus thuringiensis toxin Cry1Ac in diamondback moth (Plutella xylostella L) from lowland Malaysia

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2001
Ali H Sayyed
Abstract A field population of Plutella xylostella from Malaysia (SERD4) was divided into five sub-populations and four were selected (G2,G5) with the Bacillus thuringiensis insecticidal crystal (Cry) toxins Cry1Ac, Cry1Ab, Cry1Ca and Cry1Da. Bioassay at G6 gave resistance ratios of 88, 5, 2 and 3 for Cry1Ac, Cry1Ab, Cry1Ca and Cry1Da respectively compared with the unselected sub-population (UNSEL-SERD4). The Cry1Ac-selected population showed little cross-resistance to Cry1Ab, Cry1Ca and Cry1Da, (3-, 2- and 3-fold compared with UNSEL-SERD4), whereas the Cry1Ab-SEL sub-population showed marked cross-resistance to Cry1Ac (40-fold), much greater than Cry1Ab itself. In contrast, the Cry1Ca- and Cry1Da-SEL sub-populations showed little if any cross-resistance to Cry1Ac and Cry1Ab. The mode of inheritance of resistance to Cry1Ac was examined in Cry1Ac-selected SERD4 by standard reciprocal crosses and back-crosses using a laboratory insecticide-susceptible population (ROTH). Logit regression analysis of F1 reciprocal crosses indicated that resistance to Cry1Ac was inherited as an incompletely dominant trait. At the highest dose of Cry1Ac tested, resistance was recessive, while at the lowest dose it was almost completely dominant. The F2 progeny from a back-cross of F1 progeny with ROTH were tested with a concentration of Cry1Ac that would kill 100% of ROTH. The mortality ranged between 50 and 95% in seven families of back-cross progeny, which indicated that more than one allele on separate loci were responsible for resistance to Cry1Ac. © 2001 Society of Chemical Industry [source]

Introgression of a gene for delayed pigment gland morphogenesis from Gossypium bickii into upland cotton

PLANT BREEDING, Issue 6 2005
S. J. Zhu
Abstract The presence of gossypol and its derivatives above the WHO/FAO standards (0.02,0.04%) in cotton seed oil and meal limits its usage as food and feed. To the contrary, the presence of pigment glands filled with gossypol and its derivatives helps to protect cotton plants from phytophageous pests. Thus a desirable cultivar would have glandless seeds on a glanded plant. This paper describes results on the successful introgression of this trait from Gossypium bickii into cultivated upland cotton. Five different tri-specific hybrids (ABH1, ABH2, ABH3, ABH4 and ABH5) were obtained by crossing the amphidiploid F1 (G. arboreum × G. bickii) with different gland genotypes of G. hirsutum as male parent. The hybrids were highly sterile, and their chromosome configuration at meiosis metaphase 1 (M1) in pollen mother cell (PMC) was 2n = 52 = 41.04 I + 4.54 II + 0.57 III + 0.04 IV. All five hybrids were similar in morphological characters, except for the gland expression and gossypol contents. The hybrid (ABH3) derived from genotype Gl2Gl2gl3gl3 of upland cotton (a single gene dominant line) had completely introgressed the target trait of G. bickii. While ABH1 and ABH2, which derived from recessive (gl2gl2gl3gl3) or dominant (GlGl) glandless upland cotton genotypes, had glandless seeds too, but the density and size of the glands on the plant were reduced significantly. [source]

Identification of RAPD markers linked to recessive genes conferring siliqua shatter resistance in Brassica rapa

PLANT BREEDING, Issue 6 2003
O. Mongkolporn
Abstract Shattering of siliquae causes significant seed loss in canola (Brassica napus) production worldwide. There is little genetic variation for resistance to shatter in canola and, hence, the trait has been studied in B. rapa. Previous studies have shown two randomly segregating recessive genes to be responsible for shatter resistance. Three random amplified polymorphic DNA markers were identified as being linked to shatter resistance using bulked segregant analysis in a F3B. rapa population. The population was derived from a cross between a shatter-susceptible Canadian cultivar and a shatter-resistant Indian line. Of the three markers, RAC-3900 and RX-71000 were linked to recessive sh1 and sh2 alleles, and SAC-201300 was linked to both dominant Sh1 and Sh2 alleles. The common marker for the dominant wild-type allele for the two loci was explained to have resulted from duplication of an original locus and the associated markers through chromosome duplication and rearrangements in the process of evolution of the modern B. rapa from its progenitor that had a lower number of chromosomes. Segregation data from double heterozygous F3 families, although limited, indicated the markers were not linked to each other and provided further evidence for the duplication hypothesis. [source]

Inheritance of plant height and allelism tests of the dwarfing genes in Chinese barley

PLANT BREEDING, Issue 2 2003
J. Zhang
Abstract In order to find new dwarfing genes, the inheritance of plant height in 25 Chinese barley dwarf accessions was studied and allelism tests carried out, not only between the dwarfing genes found but also with the known dwarfing genes uz, br, sdw and denso. The results showed that out of the 25 dwarf accessions, 20 were due to monogenic recessiveness and four to digenic recessiveness. Only the short plant character in ,1974E' was controlled by a recessive together with a dominant dwarfing gene. In the present study, seven recessive and one dominant new dwarfing genes were identified. Five recessive genes were found in the monogenic mutants ,91G318', ,91D27' and ,93-597' and in the Tibetan monogenic dwarf landraces ,Jia Jiu' and ,BQK', respectively. The other two recessives were found in the Tibetan digenic dwarf landraces ,ZLL' and ,ZLLQK', and the one dominant gene in the digenic mutant ,1974E'. [source]

Inheritance of heading time in spring barley evaluated in multiple environments

PLANT BREEDING, Issue 3 2001
L. W. Gallagher
Abstract The inheritance of heading time of spring barley was studied in three extremely early genotypes IB, RL and ,Mona' (M), which is homozygous recessive for the early maturity ea8 (=eak) gene conferring extreme earliness under short daylengths and is relatively photoperiod insensitive, and five (GP, MA, PS, NU and BA) spring genotypes that are early to intermediate for heading time. Frequency distributions of F2 generations grown at Ouled Gnaou, Morocco (32°15, N), an environment which maximizes differences between photoperiod-insensitive and photoperiod-sensitive genotypes, indicated that across populations many loci were segregating in a complex Mendelian manner. IB and RL were both homozygous recessive for the ea8 gene, which conferred an early heading time. RL had partially dominant alleles at second locus (Enea8), which enhanced its earliness. Recovery of only progeny within the parental range of genotypes for heading time from the crosses of RL/M and IB/M suggests that numerous loci remained suppressed, perhaps latent, given their diverse parentage. The ea8 recessive homozygote in RL suppressed another unidentified locus which, when homozygous recessive in the absence of the ea8 recessive homozygote, conferred extreme earliness in one short daylength environment (Ouled Gnaou, Morocco) but was undetected in another environment (Davis, CA, USA). Epistatic gene action and genotype × environment effects strongly influenced heading time. In addition to a genetic system consisting of single-locus recessive homozygotes conferring photoperiod insensitivity, a second genetic system, based on dominant alleles at one or a few loci, derived from the early heading Finnish landrace ,Olli', also confers extremely early heading time under short daylengths and relative photoperiod insensitivity in the genotype GP. [source]