A highly conserved sequence on the short arm of chromosome 7 detects multiple polymorphisms.

We have isolated a human DNA fragment (laboratory acronym G98) that detects related sequences in mammals, chicken and Drosophila DNAs. This sequence has been mapped to human chromosome 7 p14-p15 by in situ hybridization. Probe G98 recognizes an insertion-deletion type polymorphism, with allelic frequencies of about 0.5, which can be detected with at least six different restriction enzymes. A second polymorphism, which can be detected in human DNA digested with TaqI, is in non-complete linkage disequilibrium with the first polymorphism. About 70% of the individuals analysed have been found to be heterozygous at this locus.