Autosomal recessive distal muscular dystrophy

The "distal myopathies" include autosomal dominant, autosomal recessive, and sporadic disorders. Two of the recessive disorders are considered to be definitive entities: Miyoshi's myopathy, which has an early adult onset and first involves the calf muscles, and distal myopathy with rimmed vacuoles. We here describe the cases of two sisters and compare them with previously reported cases. The disorder in our patients is characterised by: a) autosomal recessive inheritance; b) onset in early adult life; c) initial involvement of the tibialis anterior and peroneal muscles; d) subsequent involvement of the calf muscles spreading to the proximal muscles of the legs and, later, the arms; e) a moderately disabling evolution over a period of 10-12 years; f) marked and stably high serum levels of CK and other enzymes; g) EMG evidence of myopathic damage, with fibrillation at rest; and h) a histological picture of dystrophic myopathy, with atrophy of mainly type 2 fibres. We think that this syndrome is different from the two forms of autosomal recessive distal myopathy mentioned above.