MAPPING OF A CHROMOSOME-15 REGION INVOLVED IN LIMB-GIRDLE MUSCULAR-DYSTROPHY

A gene responsible for an autosomal recessive form of limb girdle musc ular dystrophy (LGMDP2, MIM number 253600) has been localized on chrom osome 15. After genotyping additional markers of this chromosome, two were found to flank the disease locus within an interval that was asse ssed as 7 centiMorgans. The screening of the CEPH YAC libraries with t he corresponding probes allowed the isolation of YACs which were used in fluorescence in situ hybridization to define the LGMD2 cytogenetic interval as 15q15.1-15q21.1. Four different approaches were pursued fo r the establishment of the physical map of this area which allowed the assembly of an uninterrupted YAC contig spanning an estimated 10-12 m egabases, with an average STS resolution of 140 kb or for the 25 polym orphic microsatellites on this map, of 400 kb. Twelve genes and 25 gen etic markers were positioned in this contig, which is constituted of a minimum of 10 clones.