Autosomal recessive motor and sensory neuropathy with excessive myelin outfolding.

Two Japanese persons with consanguinous parents had a motor and sensory neuropathy of the hypertrophic type with excessive myelin outfolding in the myelinated fibers. A morphometric analysis of the biopsied sural nerve was made. Excessive myelin outfolding, segmental demyelination, and remyelination and decrease in the density of both large and small myelinated fibers were evident. Using linear regression, myelin spiral length was shorter relative to axonal area. These patients may have a new variant of hereditary motor sensory neuropathy.