A Man with Episodes of Shoulder Pain and a Weak Arm

A 69 year old man presents with a history of recurrent episodes of brachial neuritis. The symptoms started at the age of 35 and the episodes were usually preceded by flu-like illnesses or infection. His son had an episode of brachial neuritis at the age of 17. The clinical picture is consistent with hereditary neuralgic amyotrophy (HNA), however genetic testing does not reveal mutations in the Septin 9 (SEPT9) gene. As only ~ half of the HNA families studied had a defect in the SEPT9 gene, mutations in other genes that have not yet been identified may be responsible for HNA.