Steroid responsive polyneuropathy

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Steroid responsive polyneuropathy in a family with a novel myelin

protein

zero mutation.

Donaghy M, Sisodiya SM, Kennett R, Mc B, Haites N, Bell C.

Department of Clinical Neurology, University of Oxford, Radcliffe

Infirmary,

Woodstock Road, Oxford OX2 6HE, UK. Joanne.Wilkinson@...

OBJECTIVE: To report a novel hereditary motor and sensory neuropathy

(HMSN)

phenotype, with partial steroid responsiveness, caused by a novel

dominant

mutation in the myelin protein zero (MPZ) gene. Most MPZ mutations lead

to

the HMSN type I phenotype, with recent reports of Dejerine-Sottas,

congenital hypomyelination, and HMSN II also ascribed to MPZ mutations.

Differing phenotypes may reflect the effect of particular mutations on

MPZ

structure and adhesivity. METHODS: Clinical, neurophysiological,

neuropathological, and molecular genetic analysis of a family presenting

with an unusual hereditary neuropathy. RESULTS: Progressive disabling

weakness, with positive sensory phenomena and areflexia, occurred in the

proband with raised CSF protein and initial steroid responsiveness.

Nerve

biopsy in a less severely affected sibling disclosed a demyelinating

process

with disruption of compacted myelin. The younger generation were so far

less

severely affected, becoming symptomatic only after 30 years. All

affected

family members were heterozygous for a novel MPZ mutation (Ile99Thr), in

a

conserved residue. CONCLUSIONS: This broadens the range of familial

neuropathy associated with MPZ mutations to include steroid responsive

neuropathy, initially diagnosed as chronic inflammatory demyelinating

polyneuropathy.