La maladie de Kennedy ou amyotrophie bulbo-spinale liée à l'X

Bulbospinal muscular atrophy (BSMA) is an X-linked late-onset neuroendocrine disorder dominated by signs of lower motor neuron loss but characterized by a phenotypic heterogeneity. We describe two cases in order to illustrate this clinical heterogeneity and summarize current knowledge and recent advances. The first patient presented progressive muscle weakness, signs of lower motor neuron loss and a sensorial peripheral neuropathy with chronic denervation. The second patient developed a sensorial disorder attributed to chronic axonal polyneuropathy, postural tremor and hyper-CK-emia. Muscle fasciculation was present in both cases. PCR testing showed an expansion of CAG with 44 ± 1 repeats, confirming Kennedy disease. BSMA may be suspected in patients presenting an atypical lower motor neuron loss or muscular disease. Early diagnosis is important to propose appropriate treatment and genetic counseling.