Monomelic amyotrophy in siblings

Monomelic amyotrophy is a rare, benign motor neuron disorder. Electrophysiologic studies are suggestive of localized chronic anterior horn cell disease. Two young siblings are reported with monomelic amyotrophy who had proximal muscle weakness confined to one arm. We propose that monomelic amyotrophy, at least in this family, is inherited as an autosomal recessive trait.