Search results for "Linkage"
showing 10 items of 363 documents
Sex-dependent genetic markers of CYP3A4 expression and activity in human liver microsomes
2007
Objective: To find genetic markers of the individual cytochrome P450 (CYP)3A expression. Methods: A large collection of liver samples phenotyped for CYP3A expression and activity was genotyped for CYP3A variants. Data were analyzed for associations between CYP3A phenotypes and genotypes, and for evidence of recent selection. Results: We report associations between the hepatic CYP3A4 protein expression level, as well as its enzymatic activity, measured as verapamil N-dealkylation, and genetic polymorphisms from two regions within the CYP3A gene cluster. One region is defined by several variants, mostly located within CYP3A7, the other by a single nucleotide polymorphism in intron 7 of CYP3A…
Linkage analysis in Usher syndrome type I (USH1) families from Spain.
1998
Usher syndrome (USH) is an autosomal recessive hereditary disorder characterised by congenital sensorineural hearing loss and gradual visual impairment secondary to retinitis pigmentosa (RP). The disorder is clinically and genetically heterogeneous. With regard to Usher type I (USH1), several subtypes have been described, the most frequent being USH1B located on chromosome 11q13.5. Of 18 USH1 families studied by linkage analysis, 12 (67%) showed significant lod score values for locus D11S527 (Zmax=14.032, theta=0.000) situated on chromosome 11q. Our findings suggest considerable genetic heterogeneity in the Spanish USH1 population. It is important to note that one of our families linked to …
Mutations in the β-tropomyosin (TPM2) gene – a rare cause of nemaline myopathy
2002
Nemaline myopathy is a clinically and genetically heterogeneous muscle disorder. In the nebulin gene we have detected a number of autosomal recessive mutations. Both autosomal dominant and recessive mutations have been detected in the genes for alpha -actin and alpha -tropomyosin 3. A recessive mutation causing nemaline myopathy among the Old Order Amish has recently been identified in the gene for slow skeletal muscle troponin T. As linkage studies had shown that at least one further gene exists for nemaline myopathy, we investigated another tropomyosin gene expressed in skeletal muscle, the beta -tropomyosin 2 gene. Screening 66 unrelated patients, using single strand conformation polymor…
The copy number variant involving part of the α7 nicotinic receptor gene contains a polymorphic inversion.
2008
The alpha7 nicotinic acetylcholine receptor gene (CHRNA7) is located at 15q13-q14 in a region that is strongly linked to the P50 sensory gating deficit, an endophenotype of schizophrenia and bipolar disorder. Part of the gene is a copy number variant, due to a duplication of exons 5-10 and 3' sequence in CHRFAM7A, which is present in many but not all humans. Maps of this region show that the two genes are in opposite orientation in the individual mainly represented in the public access human DNA sequence database (Build 36), suggesting that an inversion had occurred since the duplication. We have used fluorescent in situ hybridization to investigate this putative inversion. Analysis of inte…
Family studies in scleroderma (systemic sclerosis) demonstrating an HLA-linked increased chromosomal breakage rate in cultured lymphocytes
1988
An increased chromosomal breakage rate (ICBR) was found in 27 of 28 patients with scleroderma (systemic sclerosis, SS) - 5 with the syndrome including calcinosis cutis, Raynaud phenomenon, esophagus hypomotility, sclerodactyly and telangiectasia (CREST), 4 incomplete CREST, 1 overlapping syndrome, 18 progressive systemic sclerosis (PSS). Not only the patients, but also about half of their first-degree relatives showed an increased chromosomal breakage rate (more than 5 breaks per 100 metaphases). This character segregated as a dominant marker in nine families of scleroderma patients. In the six informative of the nine families, the ICBR trait showed close linkage with the HLA region on chro…
Clonal population structure of the chestnut blight fungus in expanding ranges in southeastern Europe.
2008
Expanding populations are often less genetically diverse at their margins than at the centre of a species' range. Established, older populations of the chestnut blight fungus, Cryphonectria parasitica, are more variable for vegetative compatibility (vc) types than in expanding populations in southeastern Europe where C. parasitica has colonized relatively recently. To test whether vc types represent clones, we genotyped 373 isolates of C. parasitica from southern Italy, Romania, Bulgaria, Macedonia, Greece and Turkey using 11 sequence-characterized amplified region (SCAR) markers. Ten SCAR loci and six vegetative incompatibility (vic) loci were polymorphic in these samples. These population…
Autosomal dominant polycystic kidney disease—in vitro culture of cyst-lining epithelial cells
1992
The major form of autosomal dominant polycystic kidney disease (ADPKD) in humans is linked to the PKD1 gene on chromosome 16p. The identity of the gene and the underlying pathogenetic mechanisms are not yet defined. Cyst-lining epithelial cells derived from a polycystic kidney were successfully grown in culture and designated MZ-PKD-1 cells. By linkage analysis, the related pedigree of the nephrectomized patient could be linked to the PKD1 gene on chromosome 16p. Thus, these cells exhibit the genotype of a mutated PKD1 gene and represent an in vitro culture model for ADPKD involving chromosome 16p. The antigenic phenotype was characterized immunohistologically by epithelial differentiation …
Data for nine autosomal STRs markers from Valencia (East Mediterranean coast of the Iberian Peninsula)
2000
Nine STRs loci have been typed in a sample from Valencia, a population from the East Mediterranean coast of the Iberian Peninsula.
Mutations in SLC20A2 link familial idiopathic basal ganglia calcification with phosphate homeostasis.
2012
Familial idiopathic basal ganglia calcification (IBGC) is a genetic condition with a wide spectrum of neuropsychiatric symptoms, including parkinsonism and dementia. Here, we identified mutations in SLC20A2, encoding the type III sodium-dependent phosphate transporter 2 (PiT2), in IBGC-affected families of varied ancestry, and we observed significantly impaired phosphate transport activity for all assayed PiT2 mutants in Xenopus laevis oocytes. Our results implicate altered phosphate homeostasis in the etiology of IBGC.
Conduct disorder and ADHD: evaluation of conduct problems as a categorical and quantitative trait in the international multicentre ADHD genetics stud…
2008
Contains fulltext : 71374.pdf (Publisher’s version ) (Closed access) Attention-deficit/hyperactivity disorder (ADHD) is typically characterized by inattention, excessive motor activity, impulsivity, and distractibility. Individuals with ADHD have significant impairment in family and peer relations, academic functioning, and show high co-morbidity with a wide range of psychiatric disorders including oppositional defiant disorder (ODD), conduct disorder (CD), anxiety disorder, depression, substance abuse, and pervasive developmental disorder (PDD). Family studies suggest that ADHD + CD represents a specific subtype of the ADHD disorder with familial risk factors only partly overlapping with t…