DNA diversity and population admixture in Anatolia.

The Turkic language was introduced in Anatolia at the start of this millennium, by nomadic Turkmen groups from Central Asia. Whether that cultural transition also had significant population-genetics consequences is not fully understood. Three nuclear microsatellite loci, the hypervariable region I of the mitochondrial genome, six microsatellite loci of the Y chromosome, and one Alu insertion (YAP) were amplified and typed in 118 individuals from four populations of Anatolia. For each locus, the number of chromosomes considered varied between 51-200. Genetic variation was large within samples, and much less so between them. The contribution of Central Asian genes to the current Anatolian gene pool was quantified using three different methods, considering for comparison populations of Mediterranean Europe, and Turkic-speaking populations of Central Asia. The most reliable estimates suggest roughly 30% Central Asian admixture for both mitochondrial and Y-chromosome loci. That (admittedly approximate) figure is compatible both with a substantial immigration accompanying the arrival of the Turkmen armies (which is not historically documented), and with continuous gene flow from Asia into Anatolia, at a rate of 1% for 40 generations. Because a military invasion is expected to more deeply affect the male gene pool, similar estimates of admixture for female- and male-transmitted traits are easier to reconcile with continuous migratory contacts between Anatolia and its Asian neighbors, perhaps facilitated by the disappearance of a linguistic barrier between them.

Turkish population data on the HLA-DO alpha, LDLR, GYPA, HBGG, D7s8, and GC loci.

We have determined the allele and genotype frequencies of six PCR-based genetic markers HLA-DQ alpha, LDLR, GYPA, HBGG, D7S8 and GC in the Turkish population (n = 361 for HLA-DQ alpha, and n = 260 for PM). All loci meet Hardy-Weinberg expectations. The frequency data can be used in forensic analyses in the Turkish population.

Allele distribution of D5S125, MAP1B5' and D5S679 microsatellite markers in Turkish spinal muscular atrophy families.

Spinal muscular atrophy (SMA) is an autosomal recessive disease and one of the most common genetic causes of death in childhood. The gene for SMA has been mapped to chromosome 5q11.2-13.3. Chromosomal distribution of the alleles of D5S125, MAP1B5' and D5S679 polymorphic microsatellite markers in 14 unrelated Turkish SMA families have been determined. It is observed that the A9 allele of D5S679 has a significant (chi 2: 3.41 p: 0.065) non-random association with mutant chromosomes.

Glyoxalase 1 (GLO1) polymorphism in eight geographical regions of Turkey.

The distribution of glyoxalase 1 (GLO1) phenotypes in eight geographical regions of Turkey was studied. The GLO1*1 allele frequency varies from 0.3630 to 0.4118, which is in good agreement with the previously estimated range of variability. Excess numbers of heterozygotes compared to the Hardy-Weinberg equilibrium were observed in all regions. The reason of this requires further investigations.

Allele frequencies of Mp6D-9 and GATT markers in 32 Turkish cystic fibrosis families.

The allele frequency of GATT and Mp6D-9 markers was investigated in 32 cystic fibrosis (CF) families. The GATT6 allele was found to be significantly associated with the delta F508 mutation. The Mp6D-9 allele 2/GATT6 haplotype was the major haplotype of the mutant alleles. Further analysis of CF alleles for population-specific mutations is underway so that a more direct approach can be taken, especially for families seeking prenatal diagnosis.

Red cell enzyme and blood group polymorphisms in Turkey.

Baseline data from Turkey is presented on phenotype and gene frequency distributions of three red cell enzyme systems (ESD, PGM1, PG1) and two blood groups (ABO, Rh). Examination of the distributions of these gene frequencies among the four geographic regions of Turkey showed that except for ESD, the Turkish population is genetically homogeneous. The gene frequencies observed in Turkey are compared with those in some countries in Europe and Asia.

Taste sensitivity to phenylthiocarbamide in Turkey.

The ability to taste phenylthiocarbamide (PTC) has been investigated in a group of 366 Turkish medical students. The incidence of non-tasters was 7.78% (t gene frequency = .279) and 12.9% (t gene frequency = .359) for females and males respectively. The frequency of non-tasters for both sexes combined was 11.2% (t gene frequency = .335).