Selected di- and tetranucleotide microsatellites from chromosomes 7, 12, 14, and Y in various Eurasian populations

Microsatellite polymorphisms of nine Eurasian populations (> 1200 chromosomes) were analyzed for the following loci: i) intronic (gt)n stretches of three T cell receptor (TCR) B loci on chromosome 7 (TCRBV6S1, TCRBV6S3, TCRBV6S7); ii) an intergenic (gt)n repeat in the region between the TCRDV3 and TCRAJ61 elements on chromosome 14; iii) two tetranucleotide simple repeats (D12S66, D12S67), not linked to known genes on chromosome 12; iv) a Y-chromosomal (gata)n polymorphism (DYS19). In general, allele frequencies and heterozygosity rates were similar, but specific alleles were missing in one or more populations. Distinct DYS19 alleles predominated in particular cohorts. Different allele frequencies were observed for the TCR loci in European and Asian populations. Tetranucleotide polymorphisms were distributed normally, whereas TCR alleles displayed bimodal frequency profiles. For TCRBV6S1 and TCRBV6S7, this profile reflects a diallelic protein polymorphism that correlates exactly with the length of the intronic repeats.