Evidence for genetic heterogeneity in hereditary neuralgic amyotrophy

Hereditary neuralgic amyotrophy (HNA) is a rare autosomal dominant disorder characterized by recurrent episodes of severe arm and shoulder pain with w eakness, atrophy, and sensory impairment in a brachial plexus distribution. Recent studies mapped the HNA locus to chromosome 17q25. Two pedigrees wit h clinically typical HNA in which markers from chromosome 17q25 do not cose gregate with the disease and in which lod scores do not support linkage to chromosome 17q25 were identified.