DETECTION OF AN INSERTION DELETION OF REGION 8Q13-Q21.2 IN A PATIENT WITH DUANE-SYNDROME - IMPLICATIONS FOR MAPPING AND CLONING A DUANE GENE

Duane syndrome (MIM126800) is an autosomal dominant disease responsibl e for 1% of all strabismus cases and has been related to a 8q12-13 con tiguous gene syndrome. We report on an insertion of chromosome region 8q13-q21.2 on to band 6q25 in a patient presenting with Duane syndrome , mental retardation, and other dysmorphisms. FISH analysis using chro mosome 8 radiation hybrid LIA2L indicated a concurrent deletion within the go rearranged region. These results were corroborated by STR-PCR analysis and FISH using YAC contig WC8.8 disclosed a deletion in 8q13. Comparison of the two known patients with Duane syndrome associated w ith deletion of go identifies a small region of overlap (SRO) of < 3 c M extending from D8S533 and D8S1767 in which a Duane syndrome locus is assigned. In addition YAC analysis in our patient showed that go-rear rangement was rather complex since go deletion and insertion occurred in two distinct segments separated by a region which maintained its lo cation on go.