Identification of a new autosomal dominant limb-girdle muscular dystrophy locus on chromosome 7.

We report the identification of a new locus for autosomal dominant limb-girdle muscular dystrophy (LGMD1) on 7q. Two of five families (1047 and 1701) demonstrate evidence in favor of linkage to this region. The maximum two-point LOD score for family 1047 was 3.76 for D7S427, and that for family 1701 was 2.63 for D7S3058. Flanking markers place the LGMD1 locus between D7S2423 and D7S427, with multipoint analysis slightly favoring the 9-cM interval spanned by D7S2546 and D7S2423. Three of five families appear to be unlinked to this new locus on chromosome 7, thus establishing further heterogeneity within the LGMD1 diagnostic classification.