Search results for "Haplotypes"
showing 10 items of 295 documents
A locus on 2p12 containing the co-regulated MRPL19 and C2ORF3 genes is associated to dyslexia.
2007
DYX3, a locus for dyslexia, resides on chromosome 2p11-p15. We have refined its location on 2p12 to a 157 kb region in two rounds of linkage disequilibrium (LD) mapping in a set of Finnish families. The observed association was replicated in an independent set of 251 German families. Two overlapping risk haplotypes spanning 16 kb were identified in both sample sets separately as well as in a joint analysis. In the German sample set, the odds ratio for the most significantly associated haplotype increased with dyslexia severity from 2.2 to 5.2. The risk haplotypes are located in an intergenic region between FLJ13391 and MRPL19/C2ORF3. As no novel genes could be cloned from this region, we hy…
Exceptional cryptic diversity and multiple origins of parthenogenesis in a freshwater ostracod.
2009
The persistence of asexual reproduction in many taxa depends on a balance between the origin of new asexual lineages and the extinction of old ones. This turnover determines the diversity of extant asexual populations and so influences the interaction between sexual and asexual modes of reproduction. Species with mixed reproduction, like the freshwater ostracod (Crustacea) morphospecies Eucypris virens, are a good model to examine these dynamics. This species is also a geographic parthenogen, in which sexual females and males co-exist with asexual females in the circum-Mediterranean area only, whereas asexual females occur all over Europe. A molecular phylogeny of E. virens based on the mit…
Major histocompatibility complex (MHC) class III genetics in two Amerindian tribes from southern Brazil: the Kaingang and the Guarani.
1997
Population genetic studies of the major histocompatibility complex (MHC) class III region, comprising C2, BF and C4 phenotypes, and molecular genetic data are rarely available for populations other than Caucasoids. We have investigated three Amerindian populations from Southern Brazil: 131 Kaingang from Ivaí (KIV), 111 Kaingang (KRC) and 100 Guarani (GRC) from Rio das Cobras. Extended MHC haplotypes were derived after standard C2, BF, C4 phenotyping and restriction fragment length polymorphism (RFLP) analysis with TaqI, together with HLA data published previously by segregation analysis. C2 and BF frequencies corresponded to other Amerindian populations. C4B*Q0 frequency was high in the GRC…
Mutations in the PDS Gene in German Families with Pendred’s Syndrome: V138F Is a Founder Mutation
2003
Pendred's syndrome, an autosomal-recessive condition characterized by congenital sensorineural hearing loss and goiter, is caused by mutations in the PDS gene. Located on chromosome 7q22-q31, it encodes a chloride-iodide transporter expressed in the thyroid, inner ear, and kidney. We investigated the PDS gene of six affected individuals from four unrelated families with Pendred's syndrome by direct sequencing. PDS mutations were identified in homozygous or compound heterozygous state in all six cases. A homozygous missense mutation leading to the amino acid substitution S133T was detected in a family of Turkish origin. The mutations found in the other affected individuals, who originate fro…
Increased Activity of Coagulation Factor XII (Hageman Factor) Causes Hereditary Angioedema Type III
2006
International audience; Hereditary angioedema (HAE) is characterized clinically by recurrent acute skin swelling, abdominal pain, and potentially life-threatening laryngeal edema. Three forms of HAE have been described. The classic forms, HAE types I and II, occur as a consequence of mutations in the C1-inhibitor gene. In contrast to HAE types I and II, HAE type III has been observed exclusively in women, where it appears to be correlated with conditions of high estrogen levels--for example, pregnancy or the use of oral contraceptives. A recent report proposed two missense mutations (c.1032C-->A and c.1032C-->G) in F12, the gene encoding human coagulation factor XII (FXII, or Hageman factor…
Moors and Saracens in Europe: estimating the medieval North African male legacy in southern Europe.
2009
To investigate the male genetic legacy of the Arab rule in southern Europe during medieval times, we focused on specific Northwest African haplogroups and identified evolutionary close STR-defined haplotypes in Iberia, Sicily and the Italian peninsula. Our results point to a higher recent Northwest African contribution in Iberia and Sicily in agreement with historical data, southern Italian regions known to have experienced long-term Arab presence also show an enrichment of Northwest African types. The forensic and genomic implications of these findings are discussed.
The gene encoding ganglioside-induced differentiation-associated protein 1 is mutated in axonal Charcot-Marie-Tooth type 4A disease
2001
We identified three distinct mutations and six mutant alleles in GDAP1 in three families with axonal Charcot-Marie-Tooth (CMT) neuropathy and vocal cord paresis, which were previously linked to the CMT4A locus on chromosome 8q21.1. These results establish the molecular etiology of CMT4A (MIM 214400) and suggest that it may be associated with both axonal and demyelinating phenotypes.
Patterns of male-specific inter-population divergence in Europe, West Asia and North Africa
2000
summary We typed 1801 males from 55 locations for the Y-specific binary markers YAP, DYZ3, SRY "!)$" and the (CA)n microsatellites YCAII and DYS413. Phylogenetic relationships of chromosomes with the same binary haplotype were condensed in seven large one-step networks, which accounted for 95% of all chromosomes. Their coalescence ages were estimated based on microsatellite diversity. The three largest and oldest networks undergo sharp frequency changes in three areas. The more recent network 3‐1A clearly discriminates between Western and Eastern European populations. Pairwise Fst showed an overall increment with increasing geographic distance but with a slope greatly reduced when compared …
Identification of somatostatin receptor type 5 gene polymorphisms associated with acromegaly.
2011
ObjectiveThe aim of this study was to characterize the genetic variance of somatostatin receptor 5 (SSTR5) and investigate the possible correlation of such variants with acromegaly risk and different disease characteristics.Design and methodsThe SSTR5 gene coding region and 2000 bp upstream region was sequenced in 48 patients with acromegaly and 96 control subjects. Further, three single nucleotide polymorphisms (SNPs) were analyzed in the same group of acromegaly patients and in an additional group of 475 age- and sex-matched controls.ResultsIn total, 19 SNPs were identified in the SSTR5 gene locus by direct sequencing. Three SNPs (rs34037914, rs169068, and rs642249) were significantly ass…
Genetic and environmental influences on the fibrinolytic system: a twin study.
2004
SummaryThe determination of heritability is a key issue to assess the predictive power of polymorphisms for disease in clinical studies. The aim of this study was to determine the heritability of proteins and activation markers of the fibrinolytic system in a large cohort of healthy twins. Heritability was calculated as 0.76 for thrombin activatable fibrinolysis inhibitor (TAFI), 0.44 for plasminogen activator inhibitor-1 (PAI-1), and 0.43 for tissue plasminogen activator. No significant genetic influence was observed for α2-antiplasmin-plasmin-complex and D-dimer. Heritability explained by single gene polymorphisms was 25.2% for TAFI 505G>A, 31.5% for 1542C>G, and 50.0% for combinati…