Key Points
- Identify novel genetic loci responsible for autosomal recessive limb-girdle muscular dystrophy in families excluded from known disease loci.
- Screened 17 Brazilian families with autosomal recessive limb-girdle muscular dystrophy and at least three affected siblings for exclusion from five known loci (LGMD2A–2E) and the dystroglycan and syntrophin genes.
- Conducted a genome-wide linkage search in two severely affected, alpha-sarcoglycan-negative families.
- Performed genetic linkage analysis in two additional alpha-sarcoglycan-positive families excluded from known loci.
- Mapped a novel autosomal recessive limb-girdle muscular dystrophy locus to chromosome 5q33-34 in two alpha-sarcoglycan-negative families with severe Duchenne-like phenotypes, designating it LGMD2F.
- Excluded the 5q33-34 locus in two alpha-sarcoglycan-positive families, confirming the existence of at least one additional unidentified gene causing autosomal recessive limb-girdle muscular dystrophy.
Structured PICO
PPopulation17 autosomal recessive (AR) limb-girdle muscular dystrophy (LGMD) Brazilian families with at least three affected sibs
IInterventionGenome-wide search and linkage analysis
OOutcomeIdentification of genetic loci responsible for autosomal recessive limb-girdle muscular dystrophy
Identifies a novel genetic locus (5q33-34) for a sixth form of autosomal recessive limb-girdle muscular dystrophy (LGMD2F).