A clinico-pathological study of chronic hereditary motor neuropathy

Benign neurogenic amyotrophy in Klinefelter's syndrome

Two cases of benign neurogenic amyotrophy associated with Klinefelter's syndrome are reported. Both presented with slowly progressive, diffuse neurogenic muscle atrophy of juvenile onset. Both had a karyotype of XXY. Amplification, by the polymerase chain reaction, of a fragment of androgen receptor that was related to bulbospinal muscular atrophy, showed no abnormality. Treatment with androgen in one case provided no benefit. Benign neurogenic amyotrophy in the Klinefelter's syndrome is likely to be an independent type of motor neuron disease and suggests that the X chromosome plays an important part in the biology of motor neurons.

Ragged-red fibres detected in paraffin sections by a monoclonal antibody to inner mitochondrial membrane

An immunohistochemical method is reported using the M-II68 monoclonal antibody, which detects mitochondrial accumulations ("ragged-red fibres") in routinely processed (formalin-fixed, paraffin-embedded) muscle tissue. Ten cases with electron-microscopically and histochemically proven mitochondrial myopathy featured 4% to 24% ragged-red fibres. In a series of 50 muscle biopsies without mitochondrial myopathy, scattered ragged-red fibres (less than 0.1%) were present in a few normal and pathological muscles. The immunohistochemical method is specific for mitochondria, does not require frozen tissue and permits rapid examination of large areas.