Normal Allele (normal + allele)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Mapping of nasopharyngeal carcinoma tumor-suppressive activity to a 1.8-megabase region of chromosome band 11q13

GENES, CHROMOSOMES AND CANCER, Issue 1 2002
Yue Cheng
Nasopharyngeal carcinoma (NPC) is a malignancy that is particularly prevalent among populations from Southern China and Southeast Asian countries. Evidence for a genetic contribution to the disease has been documented, although the genetic basis for NPC development is not yet fully understood. Previous functional evidence of tumor-suppressive activity on chromosome band 11q13 in NPC was obtained using a microcell-mediated chromosome-transfer approach with HONE1 NPC cells. In the present study, this region was subjected to a detailed investigation of microcell hybrids and their tumor segregants using microsatellite analysis to narrow down the region of tumor-suppressive activity. Fluorescence in situ hybridization was also performed with BAC and cosmid probes to confirm the microsatellite data. The critical region responsible for tumor suppression was narrowed down to a 1.8-Mb interval, which does not tolerate an additional normal allele by chromosome transfer. One or two alleles from either endogenous or exogenous chromosomes at 11q13 were consistently eliminated during tumor growth. Results of this study suggest that a candidate tumor-suppressor gene, not the MEN1 gene, maps between D11S4907 and GSTP1 in NPC. © 2002 Wiley-Liss, Inc. [source]


Keratosis Follicularis Spinulosa Decalvans is caused by mutations in MBTPS2,

HUMAN MUTATION, Issue 10 2010
Emmelien Aten
Abstract Keratosis Follicularis Spinulosa Decalvans (KFSD) is a rare genetic disorder characterized by development of hyperkeratotic follicular papules on the scalp followed by progressive alopecia of the scalp, eyelashes, and eyebrows. Associated eye findings include photophobia in childhood and corneal dystrophy. Due to the genetic and clinical heterogeneity of similar disorders, a definitive diagnosis of KFSD is often challenging. Toward identification of the causative gene we reanalyzed a large Dutch KFSD family. SNP arrays (1 M) redefined the locus to a 2.9-Mb region at Xp22.12,Xp22.11. Screening of all 14 genes in the candidate region identified MBTPS2 as the candidate gene carrying a c.1523A>G (p.Asn508Ser) missense mutation. The variant was also identified in two unrelated X-linked KFSD families and cosegregated with KFSD in all families. In symptomatic female carriers, skewed X-inactivation of the normal allele matched with increased severity of symptoms. MBTPS2 is required for cleavage of sterol regulatory element-binding proteins (SREBPs). In vitro functional expression studies of the c.1523A>G mutation showed that sterol responsiveness was reduced by half. Other missense mutations in MBTPS2 have recently been identified in patients with IFAP syndrome. We postulate that both phenotypes are in the spectrum of one genetic disorder with a partially overlapping phenotype. Hum Mutat 31:1,9, 2010. © 2010 Wiley-Liss, Inc. [source]


Phenotype variability in spinocerebellar ataxia type 2: A longitudinal family survey and a case featuring an unusual benign course of disease,,

MOVEMENT DISORDERS, Issue 5 2009
Sascha Hering MD
Abstract We report a 67 years old female patient out of a multigenerational family with spinocerebellar ataxia type 2 (SCA2) with an unusually benign course of disease. Although all SCA2 gene carriers have by now developed the predominant gait ataxia and brainstem oculomotor dysfunction, the index patient presented with a very mild course of disease, scoring only six points on the Scale for the Assessment and Rating of Ataxia after a disease duration of 13 years. Otherwise, intragenerational variability within family members such as the age at onset of disease and the course of disease was low. Reinvestigation of the genetic background variables in the SCA2 gene carrier reported here showed 27 repeats in the normal allele and 37 noninterrupted repeats in the abnormal allele. Interestingly, this patient has been taking lithium-carbonate over more than 30 years because of psychotic depression. Although anecdotic, this SCA2 case may provide promising insights into possible disease modifying mechanisms in SCA2. © 2009 Movement Disorder Society [source]


Congenital central hypoventilation syndrome from past to future: Model for translational and transitional autonomic medicine,

PEDIATRIC PULMONOLOGY, Issue 6 2009
Debra E. Weese-Mayer
Abstract The modern story of CCHS began in 1970 with the first description by Mellins et al., came most visibly to the public eye with the ATS Statement in 1999, and continues with increasingly fast paced advances in genetics. Affected individuals have diffuse autonomic nervous system dysregulation (ANSD). The paired-like homeobox gene PHOX2B is the disease-defining gene for CCHS; a mutation in the PHOX2B gene is requisite to the diagnosis of CCHS. Approximately 90% of individuals with the CCHS phenotype will be heterozygous for a polyalanine repeat expansion mutation (PARM); the normal allele will have 20 alanines and the affected allele will have 24,33 alanines (genotypes 20/24,20/33). The remaining ,10% of individuals with CCHS will have a non-PARM (NPARM), in the PHOX2B gene; these will be missense, nonsense, or frameshift. CCHS and PHOX2B are inherited in an autosomal dominant manner with a stable mutation. Approximately 8% of parents of a CCHS proband will be mosaic for the PHOX2B mutation. A growing number of cases of CCHS are identified after the newborn period, with presentation from infancy into adulthood. An improved understanding of the molecular basis of the PHOX2B mutations and of the PHOX2B genotype/CCHS phenotype relationship will allow physicians to anticipate the clinical phenotype for each affected individual. To best convey the remarkable history of CCHS, and to describe the value of recognizing CCHS as a model for translational and transitional autonomic medicine, we present this review article in the format of a chronological story, from 1970 to the present day. Pediatr Pulmonol. 2009; 44:521,535. © 2009 Wiley-Liss, Inc. [source]


A PCR-based DNA marker for detection of mutant and normal alleles of the Wx-D1 gene of wheat

PLANT BREEDING, Issue 2 2001
M. R. Shariflou
Abstract To assist waxy wheat breeding a DNA marker was developed to discriminate mutant and normal alleles at the Wx-D1 locus. This polymerase chain reaction-based marker distinguishes the mutant from the normal allele by targeting the previously reported deletion basis of the mutant. The marker codominantly identifies the normal allele of the Wx-D1 gene from the mutant allele originated from the Chinese landrace ,Baihoumai'. However, attempts with a number of primer combinations targeting this deletion failed to amplify the corresponding fragment from an unrelated wheat line (NP150) that has a mutant null allele at the same locus. This indicates that NP150 has a different mutant allele from that of ,Baihoumai'. This marker is a useful tool to identify wheat cultivars with mutant and normal alleles of the Wx-D1 gene, and is used in marker-assisted selection of the Wx-D1 gene in our waxy wheat breeding programme. [source]


Haploinsufficiency and acquired loss of Bcl11b and H2AX induces blast crisis of chronic myelogenous leukemia in a transgenic mouse model

CANCER SCIENCE, Issue 7 2009
Akiko Nagamachi
Chronic myelogenous leukemia (CML) is a hematological malignancy that begins as indolent chronic phase (CP) but inevitably progresses to fatal blast crisis (BC). p210BCR/ABL, a chimeric protein with enhanced kinase activity, initiates CML CP, and additional genetic alterations account for progression to BC, but the precise mechanisms underlying disease evolution are not fully understood. In the present study, we investigated the possible contribution of dysfunction of Bcl11b, a zinc-finger protein required for thymocyte differentiation, and of H2AX, a histone protein involved in DNA repair, to the transition from CML CP to BC. For this purpose, we crossed CML CP-exhibiting p210BCR/ABL transgenic (BAtg/,) mice with Bcl11b heterozygous (Bcl11b+/,) mice and H2AX heterozygous (H2AX+/,) mice. Interestingly, p210BCR/ABL transgenic, Bcl11b heterozygous (BAtg/,Bcl11b+/,) mice and p210BCR/ABL transgenic, H2AX heterozygous (BAtg/,H2AX+/,) mice frequently developed CML BC with T-cell phenotype and died in a short period. In addition, whereas p210BCR/ABL was expressed in all of the leukemic tissues, the expression of Bcl11b and H2AX was undetectable in several tumors, which was attributed to the loss of the residual normal allele or the lack of mRNA expression. These results indicate that Bcl11b and H2AX function as tumor suppressor and that haploinsufficiency and acquired loss of these gene products cooperate with p210BCR/ABL to develop CML BC. (Cancer Sci 2009; 100: 1219,1226) [source]


Identification of three novel 6-pyruvoyl-tetrahydropterin synthase gene mutations (226C>T, IVS3+1G>A, 116-119delTGTT) in Chinese hyperphenylalaninemia caused by tetrahydrobiopterin synthesis deficiency

HUMAN MUTATION, Issue 1 2001
Tze-Tze Liu
Abstract The enzyme 6-Pyruvoyl-tetrahydropterin synthase (PTS) deficiency is the major cause of BH4 -deficient HPA. The frequency of BH4 -deficient HPA was estimated to be around 30% among Chinese HPA population in Taiwan, which is much higher than that in Caucasian population (1.5-2% of HPA). Approximately 86% of Chinese BH4 -deficient HPA was found to be caused by PTS-deficiency. Seven mutations , namely R25G, N52S, V56M, V70D, P87S, D96N, and T106M , had been identified in Chinese PTS-deficient patients previously. In this study, five additional mutations in the PTS gene, namely 200C>T (T67M), 226C>T (L76F), IVS3+1G>A (K54X), 116-119delTGTT (K38X) and 169-171delGTG (V57del), were identified by PCR and DNA sequencing in Chinese PTS-deficient patients. The 116-119delTGTT introduces a frameshift stop after lysine of codon 38 (K38X). The G-to-A transition at the consensus sequence of splicing donor site of exon 3 (IVS3+1G>A) resulted in exon 3 skipping of the PTS transcript and caused a frameshift stop after lysine of codon 54 (K54X). The T67M and V57del mutations have been found in Caucasian PTS deficient patients, while the L76F, IVS3+1G>A, and K38X mutations are novel. None of 100 normal alleles screened was found to have the L76F substitution, which indicated that the L76F substitution is a mutation causing PTS deficiency. Hum Mutat 18:83, 2001. © 2001 Wiley-Liss, Inc. [source]


A PCR-based DNA marker for detection of mutant and normal alleles of the Wx-D1 gene of wheat

PLANT BREEDING, Issue 2 2001
M. R. Shariflou
Abstract To assist waxy wheat breeding a DNA marker was developed to discriminate mutant and normal alleles at the Wx-D1 locus. This polymerase chain reaction-based marker distinguishes the mutant from the normal allele by targeting the previously reported deletion basis of the mutant. The marker codominantly identifies the normal allele of the Wx-D1 gene from the mutant allele originated from the Chinese landrace ,Baihoumai'. However, attempts with a number of primer combinations targeting this deletion failed to amplify the corresponding fragment from an unrelated wheat line (NP150) that has a mutant null allele at the same locus. This indicates that NP150 has a different mutant allele from that of ,Baihoumai'. This marker is a useful tool to identify wheat cultivars with mutant and normal alleles of the Wx-D1 gene, and is used in marker-assisted selection of the Wx-D1 gene in our waxy wheat breeding programme. [source]


The occurrence of dominant spinocerebellar ataxias among 251 Finnish ataxia patients and the role of predisposing large normal alleles in a genetically isolated population

ACTA NEUROLOGICA SCANDINAVICA, Issue 3 2005
V. Juvonen
Objectives,,, Frequency and distribution of dominant ataxias caused by dynamic mutations may vary in different populations, which has been explained on the basis of relative frequency of predisposing normal alleles. The aim of the study was to evaluate the occurrence of spinocerebellar ataxias (SCAs) and dentatorubral-pallidoluysian atrophy (DRPLA) in Finland, and to investigate the role of predisposing normal alleles in a genetically homogenous population. Material and methods,,, Mutation analyses for SCA1, 2, 3, 6, 7, 8, 10, 12, 17, and DRPLA and frataxin genes were performed for 251 unrelated Finnish patients who presented with progressive ataxia disorder. Results,,, Expansions of SCA1, SCA2, SCA6, SCA7, SCA8, and SCA17 genes were detected in 2, 1, 1, 7, 22, and 1 patients, respectively. Altogether, 39 and 7% of dominant and sporadic SCA patients, respectively, harboured expansions at some of the investigated loci. Normal variation, collected from 477 to 502 chromosomes at each disease loci, revealed that Finns were different from the Japanese but largely similar to other Caucasians. Conclusions,,, Lack of SCA3 and excess of SCA8 are characteristic to the Finnish population. Homozygosity for the SCA8 expansion increases penetrance. Frequencies of large normal alleles at the SCA loci predict poorly prevalence of the respective diseases in Finland. Prioritization in DNA testing, based on ethnic origin and geographical location, is recommendable in Finland, and analogous approach may be applied to other countries as well. [source]