_:vb50946916 . _:vb50946916 "A brachial plexus neuropathy that is characterized by acute, recurrent episodes of brachial plexus neuropathy with muscle weakness and atrophy preceded by severe pain in the affected arm, and that has_material_basis_in heterozygous mutation in the SEPT9 gene on chromosome 17q25." . _:vb50946916 . _:vb50946916 "url:https://medlineplus.gov/genetics/condition/hereditary-neuralgic-amyotrophy/" . _:vb50946916 . _:vb50946916 .