The Y-27H39 polymorphism in a Japanese population.

We studied 184 Japanese males for the tetranucleotide TAGA repeat polymorphism at the Y-27H39 locus on the Y chromosome, and discovered a new allele, tentatively named F. Direct sequencing of Y-27H39 alleles revealed that the new allele (206 nt) is larger than allele E (202 nt) by 1 repeat unit. The six alleles differ only in the number of repeats, the flanking sequences being constant. The allele frequencies are different in Japanese and Caucasians.