Late-onset autosomal recessive limb-girdle muscular dystrophy with rimmed vacuoles

We report on two siblings with late-onset, limb-girdle muscular dystrophy (LGMD) inherited in an autosomal recessive manner. The LGMD was characterized by many rimmed vacuoles and reduced expression of the laminin beta1 chain in skeletal muscle. Both patients developed a progressive wasting and weakness of limb-girdle muscles in the late forties or early fifties; their facial, ocular, bulbar, and cardiac muscles were not involved. Histopathology of skeletal muscles biopsies showed typical dystrophic changes with many rimmed vacuoles. The immunoreactivity of the laminin beta1 chain was reduced in the muscle fibers, while dystrophin, sarcoglycans, beta-dystroglycan, dysferlin, and other laminin components were normally expressed. A mutation search revealed that no mutation existed in the coding region of the calpain 3, telethonin and UDP-N-acetylglucosamine 2-epimerase/N-acetylmanosamine kinase (GNE) genes. We conclude that this autosomal recessive LGMD is unknown and characterized by its late onset, rimmed vacuoles and reduction of the laminin beta1 chain in muscle fibers.