SEQUENCE VARIATION OF A HYPERVARIABLE SHORT TANDEM REPEAT AT THE D1S1656 LOCUS

A short tandem repeat at the D1S1656 locus was sequenced in 45 selecte d alleles and 13 different alleles were found which were designated ac cording to the total number of repeats. This STR is a compound hyperva riable STR consisting of blocks of (TAGR) repeats with a basic sequenc e structure (TAGA)(4)(TGA)(0-1)(TAGA)(6-16)(TAGG)(0-1)(TG)(5). The pre sence of a TGA, probably due to an A deletion in the fifth TAGA repeat leads to intermediate a.3 alleles. Population data showed that this i s a highly polymorphic STR with a heterozygosity of more than 0.89. Th is fact together with its simple structure and small size (129-168 bp) makes this STR one of the most interesting DNA polymorphisms for fore nsic and genetic purposes.