Sequence variation of allele 27 at the D1S80 locus

D1S80 subtyping by PCR-RFLP: new nomenclature and further characterization

In a previous study, we screened out sequence variations within alleles at the D1S80 locus of a Japanese population using PCR-RFLP with EcoRII as a restriction enzyme. In the present study, through analyzing the alleles in a Chinese population, we were able to demonstrate four new electrophoretic band patterns that were complementary to the Japanese data. After summarizing the band patterns and sequencing results of these two populations, we established a new nomenclature for the PCR-RFLP band patterns, closely relating them to their corresponding sequences so that the new types could be designated easily and accurately. After PCR-RFLP subtyping, nineteen alleles in the Chinese population were revealed to have a total of thirty-seven subtypes. The discrimination power of this locus in the Chinese population was elevated from 0.974 to 0.988, and the Hardy-Weinberg equilibrium in this population showed no deviation when checked. Two samples typed as homozygotes 24/24 and 30/30 were identified to be actually heterozygous according to their band patterns. The result was supported by the sequencing analysis of the two samples in which overlapping of eight and eleven repeat units, respectively, were revealed. The heterozygosity was thus elevated from 0.85 to 0.87. The present study proved that PCR-RFLP was an effective method for subtyping D1S80 alleles in the Chinese.