Application of a novel multiplex polymerase chain reaction system for 12 X-chromosomal short tandem repeats to a Japanese population study

The analysis of X-chromosomal short tandem repeat (X-STR) polymorphisms has been the focus of attention in several researches, mainly due to its applicability in the investigation of complex kinship cases. A new 12 X-STR multiplex system (GATA172D05, DXS7423, DSX6809, DXS10134, DXS7132, DXS9902, DXS6789, DXS10074, DXS8378, DXS9898, DXS10147, and GATA31E08) was developed and applied to a Japanese population study. DNA samples from 290 males and 160 females were successfully analyzed using the 12 X-STR multiplex system. No mutation was detected in the kinship cases involving 34 family trios. The combined powers of discrimination of the 12 X-STR loci in males and females were 0.999997 and 0.9999999996, respectively. We conclude that the combined analysis of 12 X-STR loci using this single multiplex polymerase chain reaction system is a powerful tool in forensic DNA testing.