Search results for "Gene Frequency"
showing 10 items of 337 documents
Molecular Basis Of Mild Hyperphenylalaninaemia In Turkey
2000
Öz bulunamadı.
Exon deletions of the phenylalanine hydroxylase gene in Italian hyperphenylalaninemics
2009
A consistent finding of many studies describing the spectrum of mutant phenylalanine hydroxylase (PAH) alleles underlying hyperphenylalaninemia is the impossibility of achieving a 100% mutation ascertainment rate using conventional gene-scanning methods. These methods include denaturing gradient gel electrophoresis (DGGE), denaturing high performance liquid chromatography (DHPLC), and direct sequencing. In recent years, it has been shown that a significant proportion of undetermined alleles consist of large deletions overlapping one or more exons. These deletions have been difficult to detect in compound heterozygotes using gene-scanning methods due to a masking effect of the non-deleted al…
Effectiveness of screening for known mutations in Sicilian patients with "probable" familial hypercholesterolemia.
2002
Background and Aim: More than 750 mutations in the low-density lipoprotein (LDL) receptor gene are currently known to cause familial hypercholesterolemia (FH), but the array of mutations varies considerably in different populations. The definition of essentially all the LDL receptor gene mutations in a population is therefore a prerequisite for the implementation of nation-wide genetic testing for FH. Methods and Results: In this study, a screening strategy based on PCR-enzymatic digestion and PCR-allele specific hybridisation procedures was used to evaluate the frequency distributions of 11 known mutations in a cohort of 214 unrelated subjects meeting the diagnostic criteria of "probable" …
HUMAN LEUKOCYTE ANTIGEN POLYMORPHISMS IN ITALIAN PRIMARY BILIARY CIRRHOSIS: A MULTICENTER STUDY OF 664 PATIENTS AND 1992 HEALTHY CONTROLS
2008
Genetic factors are critical in determining susceptibility to primary biliary cirrhosis (PBC), but there has not been a clear association with human leukocyte antigen (HLA) genes. We performed a multicenter case-control study and analyzed HLA class II DRB1 associations using a large cohort of 664 well-defined cases of PBC and 1992 controls of Italian ancestry. Importantly, healthy controls were rigorously matched not only by age and sex, but also for the geographical origin of the proband four grandparents (Northern, Central, and Southern Italy). After correction for multiple testing, DRB1*08 [odds ratio (OR), 3.3; 95% confidence interval (CI), 2.4-4.5] and DRB1*02 (OR 0.9; 95% CI 0.8-1.2) …
Genetic heterogeneity in ADHD: DAT1 gene only affects probands without CD
2008
Contains fulltext : 70183.pdf (Publisher’s version ) (Closed access) Previous studies have found heterogeneous association between DAT1-3'-UTR-VNTR and attention deficit hyperactivity disorder (ADHD). Various proportions of conduct disorder (CD) comorbidity in their ADHD samples may partially explain the observational discrepancies. Evidence for this comes from family and twin studies which found ADHD probands with CD (ADHD + CD) are genetically different from those without CD (ADHD - CD). Genotypes of 20 DAT1 markers were analyzed in 576 trios, consisting of 141 ADHD + CD and 435 ADHD - CD. In addition to the classical TDT test, a specific genetic heterogeneity test was performed to identi…
Molecular genetics of autosomal dominant retinitis pigmentosa (ADRP): a comprehensive study of 43 Italian families
2005
Retinitis pigmentosa is the most common form of retinal degeneration and is heterogeneous both clinically and genetically. The autosomal dominant forms ( ADRP) can be caused by mutations in 12 different genes. This report describes the first simultaneous mutation analysis of all the known ADRP genes in the same population, represented by 43 Italian families. This analysis allowed the identification of causative mutations in 12 of the families (28% of the total). Seven different mutations were identified, two of which are novel (458delC and 6901C --> T (P2301S), in the CRX and PRPF8 genes, respectively). Several novel polymorphisms leading to amino acid changes in the FSCN2, NRL, IMPDH1, and…
Role of PTPRJ genotype in papillary thyroid carcinoma risk
2010
The strong genetic predisposition to papillary thyroid carcinoma (PTC) might be due to a combination of low-penetrance susceptibility variants. Thus, the research into gene variants involved in the increase of susceptibility to PTC is a relevant field of investigation. The gene coding for the receptor-type tyrosine phosphatase PTPRJ has been proposed as a cancer susceptibility gene, and its role as a tumor suppressor gene is well established in thyroid carcinogenesis. In this study, we want to ascertain the role of PTPRJ genotype in the risk for PTC. We performed a case–control study in which we determined the PTPRJ genotype for the non-synonymous Gln276Pro and Asp872Glu polymorphisms by PC…
Avian Clock gene polymorphism: evidence for a latitudinal cline in allele frequencies
2007
In comparison with most animal behaviours, circadian rhythms have a well-characterized molecular genetic basis. Detailed studies of circadian clock genes in 'model' organisms provide a foundation for interpreting the functional and evolutionary significance of polymorphic circadian clock genes found within free-living animal populations. Here, we describe allelic variation in a region of the avian Clock orthologue which encodes a functionally significant polyglutamine repeat (ClkpolyQcds), within free-living populations of two passerine birds, the migratory bluethroat (Luscinia svecica) and the predominantly nonmigratory blue tit (Cyanistes caeruleus). Multiple ClkpolyQcds alleles were foun…
Direct Identification of Each Specific Mutation in Codon 12 and 13 of ci-ki-ras2 by SSCP Analysis
1998
We compared the SSCP behaviour of the DNA fragments containing c-ki-ras 2 wild type 12 and 13 codons or each of the 12 possible point mutated sequences in these two codons. We found that a single electrophoresis condition was sufficient to distinguish each specific mutation from the other 11 and from the wild type sequence. This observation makes it possible to identify each specific mutation directly by SSCP without any need for reamplification and sequencing.
Alpha1-antitrypsin heterozygosity plays a positive role in attainment of longevity.
2007
Genes involved in cardiovascular diseases (CVD) play an opposite role in human longevity. The alpha1-antitrypsin (AAT) is a serine-protease inhibitor required for the prevention of proteolytic tissue damage, by neutrophil elastase. The role of AAT in CVD has not been definitively assessed and its effect on longevity has not yet fully been studied. To clarify these points, we have studied the distribution of AAT allele variants in 3 cohorts: 127 young patients affected by acute myocardial infarction (AMI), 255 young controls and 143 centenarians from Sicily. The Z allele frequency was most frequent in centenarians (13.3%), intermediate in healthy young controls (3.1%) and less frequent in AM…