title: A Novel Asp121Asn Mutation of Myelin Protein Zero Is Associated with Late-Onset Axonal Charcot-Marie-Tooth Disease, Hearing Loss and Pupil Abnormalities.
abstract: Myelin protein zero (MPZ) is a major component of compact myelin in peripheral nerves. Mutations in MPZ have been associated with different Charcot-Marie-Tooth disease (CMT) phenotypes (CMT1B, CMT2I/J, CMTDI), Dejerine-Sottas syndrome, and congenital hypomyelination neuropathy. Here, we report phenotypic variability in a four-generation Chinese family with the MPZ mutation Asp121Asn. Genetic testing was performed on nine family members and 200 controls. Clinical, electrophysiological and skeletal muscle MRI assessments were available for review in six family members. A novel heterozygous missense mutation, Asp121Asn, was observed in five affected members of the family. Unaffected relatives and 200 normal controls were without the mutation. Four of the affected members of the family displayed late-onset, predominantly axonal sensory and motor neuropathy, pupil abnormalities, and progressive sensorineural hearing loss. One young affected member presented with Argyll-Robertson pupils and diminished deep tendon reflexes in the lower limbs. The MPZ mutation Asp121Asn may be associated with late-onset axonal neuropathy, early onset hearing loss and pupil abnormalities. Our report expands the number and phenotypic spectrum of MPZ mutations.
authors: Department of Neurology, Peking University Third HospitalBeijing, China; Department of Neurology, China-Japan Friendship HospitalBeijing, China.
authors: Xiaohui
authors: X
authors: Duan
authors: Department of Neurology, China-Japan Friendship Hospital Beijing, China.
authors: Weihong
authors: W
authors: Gu
authors: Department of Neurology, China-Japan Friendship Hospital Beijing, China.
authors: Ying
authors: Y
authors: Hao
authors: Department of Neurology, China-Japan Friendship Hospital Beijing, China.
authors: Renbin
authors: R
authors: Wang
authors: Department of Radio-Diagnosis, China-Japan Friendship Hospital, Beijing China.
authors: Hong
authors: H
authors: Wen
authors: Department of Neurology, China-Japan Friendship Hospital Beijing, China.
authors: Shaojie
authors: S
authors: Sun
authors: Department of Neurology, China-Japan Friendship Hospital Beijing, China.
authors: Jinsong
authors: J
authors: Jiao
authors: Department of Neurology, Peking University Third Hospital Beijing, China.
authors: Dongsheng
authors: D
authors: Fan
keywords: Charcot–Marie–Tooth disease; hearing loss; myelin protein zero; novel mutation; pupil abnormalities