A new form of autosomal dominant limb-girdle muscular dystrophy (LGMD1G) with progressive fingers and toes flexion limitation maps to chromosome 4p21.
Limb-girdle muscular dystrophy (LGMD) is a genetic disorder characterized by progressive weakness of pelvic and scapular girdles and great clinical variability. It is a highly heterogeneous disease with 16 identified loci: six of them autosomal dominant (AD) (LGMD1) and 10 autosomal recessive (AR) (LGMD2). The responsible genes are known for three of the AD-LGMD and for all 10 AR-LGMD. Linkage analysis excluded these 16 loci in a Brazilian-Caucasian family with 12 patients affected by AD late-onset LGMD associated with progressive fingers and toes flexion limitation. Biceps muscle biopsy from one of the patients showed a predominantly myopathic histopathological pattern, associated with rimmed vacuoles. A genomewide scan was performed which mapped a new locus for this disorder at 4p21 with a maximum two-point lod score of 6.62 for marker D4S2964. Flanking markers place this locus between D4S2947 and D4S2409, within an interval of 9 cM. We propose to classify this AD form of LGMD as LGMD1G.
Starling
Alessandra
A
Human Genome Research Center, Department of Biology, University of São Paulo, São Paulo, Brazil.
Kok
Fernando
F
Passos-Bueno
Maria Rita
MR
Vainzof
Mariz
M
Zatz
Mayana
M
D002874:Chromosome Mapping; D002894:Chromosomes, Human, Pair 4; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D005385:Fingers / Q000002:abnormalities*; D005799:Genes, Dominant; D008040:Genetic Linkage; D006239:Haplotypes; D006801:Humans; D008297:Male; D009132:Muscles / Q000473:pathology; D049288:Muscular Dystrophies, Limb-Girdle / Q000097:blood / Q000235:genetics* / Q000503:physiopathology; D010375:Pedigree; D014034:Toes / Q000002:abnormalities*
D003402:Creatine Kinase