Polymorphism of nine X chromosomal STR loci in Koreans

This study describes the polymorphism of the nine STR loci on the X chromosome, DXS6803, DXS8378, GATA164A09, DXS7132, DXS7133, DXS9895, DXS9898, DXS6789, and DXS6795 in Koreans. In each locus, 4-10 alleles were noted and the allelic distribution patterns were the same for males and females. Heterozygosity in females ranged from 0.42 to 0.84. Among the 303 father-daughter or mother-child pairs examined 29 cases of mutation were found, 13 at the DXS6803 locus, 2 at DXS8378, 4 at DXS164A09,3 at DXS7132, 1 at DXS7133, 2 at DXS9895, 2 at DXS9898, 1 at DXS6789 and 1 at DXS6795. In 208 families including 180 fathers and 177 mothers, 530 different haplotypes were found. Unlike the STR loci on the Y chromosome, cases showing recombination were frequent, and in combination with mutation this made it difficult to discriminate the exclusion cases from those with mutation or recombination based on the haplotype. Details of X chromosomal STRs in Koreans which would be useful for a future large scale database are described.