Allele frequencies and sequence characteristics of D2S1242 STR locus in Chinese population.

Sequence characteristics and allele frequencies of D2S1242 short tandem repeat (STR) locus were determined in a Chinese population using polymerase chain reaction (PCR) and sequence analysis. In 213 individuals studied, 32 genotypes representing the products of ten D2S1242 alleles were differentiated. The allele frequencies ranged from 0.002 to 0.234, and all the five most common alleles detected had frequencies over 10%. The observed and expected genotype values provided a complete fit to the Hardy-Weinberg equilibrium. The sequence structure of each D2S1242 allele showed a tetranucleotide repeat, and alleles 9-14 had different sequence structures compared to alleles 15-19. The power of discrimination was 0.94, showing a high degree of polymorphism as in other population data.