The coding region of the human DLX6 gene contains a polymorphic CAG/CCG repeat

The region on chromosome 7q21-22 is frequently altered in several human neo plasias such as uterine leiomyoma, myeloid leukemia and breast cancer. The same region has also been linked to split hand/split foot malformation type 1 and to involutional osteoporosis. Our analysis of genes that map to this region has led to the identification of the so far unknown first exon of t he homeobox gene DLX6, a mammalian homologue of the Drosophila distal-less gene. Distal-less as a downstream target of the trithorax transcription fac tors. Translocations involving the mammalian homologue of tlithorax, ALL-1, leading to its constitutive activation cause leukemia. We describe here th at the first exons of human and mouse DLX6 genes contain a multiple trinucl eotide repeat region. We have analyzed the CAG repeat length in 90 subjects and were able to identify five alleles with 11 to 20 CAG repeats.