Characterization of Y-chromosomal short tandem repeat markers in Pakistani populations.

The Y chromosome microsatellite markers have been extensively used for population genetic studies and in individual identification and paternity testing in forensic medicine. In the present study, we report the data of five male-specific, polymorphic microsatellites in 740 unrelated male individuals from 12 different ethnic groups of Pakistan. The overall diversities of these individual loci in Pakistan ranged from 0.236 to 0.799. The total haplotypes identified were 152, and of these, 70 different haplotypes were present in only single individuals. Two haplotypes were found more frequently, 9_8_17_11_24 (13.5%) and 9_8_17_11_25 (8.6%), showing population-specific clustering in the Mohanna and the Brahui, respectively. An overall haplotype diversity of 0.965 in Pakistan suggested a high power of discrimination for these loci. Few populations, particularly the Mohanna and the Balti, showed lower haplotype diversity values for these loci (0.662 and 0.758, respectively). This set of microsatellite loci reported in the study can be used for population genetics and forensic medicine analysis. This study also demonstrates the importance of studying haplotype distribution pattern in population genetics.

Prevalence of the C677T single-nucleotide polymorphism in the methylenetetrahydrofolate reductase gene among Pakistani ethnic groups.

Methylenetetrahydrofolate reductase is an important enzyme in metabolism of homocysteine, and a mutation in the gene predisposes individuals to several disorders related to homocysteine levels. Polymorphism at C677T shows marked heterogeneity based upon ethnicity and geographical location. Pakistani population consists of various ethnic groups confined to different regions of the country where congenital and genetic defects are a major health concern. We have analyzed the distribution of C677T alleles in different Pakistani ethnic groups. A cross-sectional study was conducted from all the four provinces of the country with samples representing the 14 different ethnic clans. A questionnaire with details of their ethnic origin was used, and informed consent was obtained. Blood samples from 701 individuals were collected for DNA isolation and subsequent C677T single-nucleotide polymorphism determination. The data were statistically analyzed. The study revealed that genotypic frequency for CC varied from 0.89 (Mohanna) to 0.38 (Hazara), CT from 0.56 (Hazara) to 0.11 (Mohanna), and TT from 0.06 to 0. Our data revealed a varied distribution of C677T mutation. This information could be helpful for designing future public health strategies, as it can be used to predict the prevalence of several disorders associated with genetic predisposition due to methylenetetrahydrofolate reductase C677T alleles.