Home About us Contact
|
Home About us Contact | ||
|
|
||
Recessive Mode (recessive + mode)
Kinds of Recessive Mode Selected AbstractsPalmoplantar hyperkeratosis in Irish terriers: evidence of autosomal recessive inheritanceJOURNAL OF SMALL ANIMAL PRACTICE, Issue 2 2000H. Binder An abnormal development of the epidermis of the footpad was observed in Irish terriers. At the age of six months, the affected animals developed smooth parchment-like footpads. The pad epidermis then hardened and grew lateral cone-like protrusions of up to 5 mm in diameter. Fissures and cracks developed and these predisposed the animal to secondary infection. The repeated occurrence in subsequent generations led to the assumption of a hereditary form of hyperkeratosis. Evidence for an autosomal recessive mode of inheritance was derived from a retrospective analysis of the breeder's records. The clinical, histopathological and ultrastructural features of the disease are presented and the genetic transmission and its implications discussed. [source] Frequency analysis and clinical characterization of different types of spinocerebellar ataxia in Serbian patientsMOVEMENT DISORDERS, Issue 2 2006a 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] Differences in age at onset and familial aggregation between clinical types of idiopathic Parkinson's diseaseMOVEMENT DISORDERS, Issue 9 2004Alexei Korchounov MD Abstract Idiopathic Parkinson's disease (PD) can be subdivided by its patterns of motor symptoms into tremor-dominant (TDT), akinetic-rigid (ART), and mixed type (MT). Our objective was to determine whether age at onset and family history are different in these three types. In total, 366 patients with PD were assigned in a standardized approach to one of the three subtypes. Age at onset and family history were obtained in all patients and all presumably affected family members were examined. Mean ages at disease onset were similar in all three groups, but distribution of age at onset was markedly different: monophasic in TDT with a peak around 60 years, biphasic in ART with two peaks, one in the middle of the sixth decade (earlier onset, ART-EO), another during the first half of the seventh decade (later onset, ART-LO), and increasing with age only in MT patients A positive family history was significantly associated only with TDT (odds ratio = 5.7) and ART-EO (odds ratio = 7.8), but not with MT or ART-LO patients. Segregation analysis suggested an autosomal recessive mode of transmission in ART-EO and an autosomal dominant mode of transmission in TDT. © 2004 Movement Disorder Society [source] Phenotypic characterisation of autosomal recessive PARK6-linked parkinsonism in three unrelated Italian families,MOVEMENT DISORDERS, Issue 6 2001Anna R. Bentivoglio MD Abstract The clinical features of nine patients (three women and six men) affected by PARK6-linked parkinsonism, belonging to three unrelated Italian families, are reported. The occurrence of affected men and women within one generation suggested an autosomal recessive mode of inheritance in all three families. Mean age at disease onset was 36 ± 4.6 years; all cases except one presented with asymmetrical signs, consisting of tremor and akinesia of one upper limb or unilateral short step gait. Affected individuals had a mean age of 57 ± 8.5 years, and average disease duration was 21 ± 7.8 years. Parkinsonian features included benign course, early onset of drug-induced dyskinesias, and a good and persistent response to levodopa. There were no other associated features (i.e., pyramidal or cerebellar signs, dysautonomia, or diurnal fluctuations unrelated to drug treatment). Cognition was unaffected. The clinical picture was remarkably similar in all patients; no relevant family-related differences were found. PARK6 disease is a new form of early-onset parkinsonism without other atypical clinical features. © 2001 Movement Disorder Society. [source] Marinesco-Sjögren syndrome with atrophy of the brain stem tegmentum and dysplastic cytoarchitecture in the cerebral cortexNEUROPATHOLOGY, Issue 5 2008Kenji Sakai Marinesco-Sjögren syndrome (MSS) is a progressive multisystem disease with autosomal recessive inheritance characterized by cataracts, mental retardation, and cerebellar ataxia. Recently, two causative genes for MSS, SIL1 and SARA2, have been identified. On the other hand, the histopathologic features of the CNS in this syndrome have not yet been clarified in detail. We report here the features of an autopsy case of MSS with progressive myopathy, in which atrophy of the cerebellum and brain stem tegmentum, retinal degeneration, and dysplastic cytoarchitecture in the cerebral cortex were evident. An elder brother of the patient showed quite similar symptoms, implying an autosomal recessive mode of inheritance. However, we detected no mutations in the available genes. This case appears to represent an unusual example of MSS manifesting widespread developmental anomaly and neuronal degeneration in the CNS. [source] Myocilin gene implicated in primary congenital glaucomaCLINICAL GENETICS, Issue 4 2005K Kaur Primary congenital glaucoma (PCG) has been associated with CYP1B1 gene (2p21), with a predominantly autosomal recessive mode of inheritance. Our earlier studies attributed CYP1B1 mutations to only 40% of Indian PCG cases. In this study, we included 72 such PCG cases where CYP1B1 mutations were detected in only 12 patients in heterozygous condition, implying involvement of other gene(s). On screening these patients for mutations in myocilin (MYOC), another glaucoma-associated gene, using denaturing high-performance liquid chromatography followed by sequencing, we identified a patient who was double heterozygous at CYP1B1 (c.1103G>A; Arg368His) and MYOC (c.144G>T; Gln48His) loci, suggesting a digenic mode of inheritance of PCG. In addition, we identified the same MYOC mutation, implicated for primary open angle glaucoma, in three additional PCG patients who did not harbor any mutation in CYP1B1. These observations suggest a possible role of MYOC in PCG, which might be mediated via digenic interaction with CYP1B1 and/or an yet unidentified locus associated with the disease. [source] Autosomal Dominant Inheritance of Centrotemporal Sharp Waves in Rolandic Epilepsy FamiliesEPILEPSIA, Issue 12 2007Bhavna 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] Estimation of P -value of MAX test with double triangle diagram for 2 × 3 SNP case-control tablesGENETIC EPIDEMIOLOGY, Issue 6 2010Katsura Hirosawa Abstract Single nucle otide polymorphisms (SNPs) are the most popular markers in genetic epidemiology. Multiple tests have been applied to evaluate genetic effect of SNPs, such as Pearson's test with two degrees of freedom, three tests with one degree of freedom (,2 tests for dominant and recessive modes and Cockran-Armitage trend test for additive mode) as well as MAX3 test and MAX test, which are combination of four tests mentioned earlier. Because MAX test is a combination of Pearson's test of two degrees of freedom and two tests of one degree of freedom, the probability density function (pdf) of MAX statistics does not match pdf of ,2 distribution of either one or two degrees of freedom. In order to calculate P -value of MAX test, we introduced a new diagram, Double Triangle Diagram, which was an extension of de Finetti diagram in population genetics which characterized all of the tests for 2 × 3 tables. In the diagram the contour lines of MAX statistics were consisted of elliptic curves and two tangent lines to the ellipses in the space. We normalized the ellipses into regular circles and expressed P -value of MAX test in an integral form. Although a part of the integral was not analytically solvable, it was calculable with arbitrary accuracy by dividing the area under pdf into finite rectangles. We confirmed that P -values from our method took uniform distribution from 0 to 1 in three example marginal count sets and concluded that our method was appropriate to give P -value of MAX test for 2 × 3 tables. Genet. Epidemiol. 34:543,551, 2010. © 2010 Wiley-Liss, Inc. [source] An optimal dose-effect mode trend test for SNP genotype tablesGENETIC EPIDEMIOLOGY, Issue 2 2009Ryo 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] | |||||||||||||