Limb-girdle muscular dystrophy type 1H (LGMD1H) is an autosomal dominant disorder characterized by adult onset of progressive proximal muscle weakness affecting both the upper and lower limbs (Bisceglia et al., 2010).
For a phenotypic description and ... Limb-girdle muscular dystrophy type 1H (LGMD1H) is an autosomal dominant disorder characterized by adult onset of progressive proximal muscle weakness affecting both the upper and lower limbs (Bisceglia et al., 2010). For a phenotypic description and a discussion of genetic heterogeneity of autosomal dominant limb-girdle muscular dystrophy, see LGMD1A (159000).
Bisceglia et al. (2010) reported a 4-generation family from southern Italy segregating limb-girdle muscular dystrophy in an autosomal dominant pattern of inheritance. Five family members presented with slowly progressive muscle weakness, initially affecting the lower limbs and later ... Bisceglia et al. (2010) reported a 4-generation family from southern Italy segregating limb-girdle muscular dystrophy in an autosomal dominant pattern of inheritance. Five family members presented with slowly progressive muscle weakness, initially affecting the lower limbs and later involving the upper limbs, with onset between 39 and 50 years of age. There was hypotrophy of upper and lower limb-girdle muscles, hyporeflexia, calf hypertrophy, and increased serum creatine kinase. A second group of younger family members had a possibly less severe phenotype with calf hypertrophy, but no muscle weakness and normal serum creatine kinase when examined. These individuals were considered affected for linkage analysis. EMG studies in 2 older patients showed a myopathic pattern with decreased duration of motor unit potentials and no evidence of denervation. Skeletal muscle biopsies of 4 older affected individuals showed abnormal fiber type size and shape variation, increased connective tissues, and occasional centralized nuclei. One biopsy showed ragged-red fibers with subsarcolemmal accumulation of mitochondria, and 2 biopsies showed absence of cytochrome c oxidase staining as well as evidence of mtDNA deletions. Overall, the biopsy results suggested a defect in mitochondrial function.