A polymorphic complex dinucleotide repeat at the telomeric D8S7 locus.

Two cosmids isolated from a flow-sorted chromosome 8 library by hybridization with pSW50 (D8S7) were screened for GT microsatellite sequences. Both contained a positive 900-bp Hind III-Xba I fragment. Sequencing revealed a complex dinucleotide repeat. Flanking oligonucleotide primers were synthesized, and the polymerase chain reaction products produced by these primers were typed within the CEPH panel of families. A two-allele polymorphism was identified that is in linkage disequilibrium with a previously described insertion-deletion polymorphism at this locus.