We report two new MPZ mutations causing congenital hypomyelinating neuropathies; c.368_382delGCACGTTCACTTGTG (in-frame deletion of five amino acids) and c.392A > G, Asn131Ser. Each child had clinical and electrodiagnostic features consistent with an inherited neuropathy, confirmed by sural nerve biopsy. The cases illustrate the clinically heterogeneity that exists even within early-onset forms of this disease. They also lend additional support to the emerging clinical and laboratory evidence that impaired intracellular protein trafficking may represent the cause of some congenital hypomyelinating neuropathies.
Bibliographical noteFunding Information:
The authors thank Rebecca D. Folkerth, MD for her interpretation of the nerve biopsy results in Case 2. PBK is supported by: NINDS K08 NS048180. SS is supported by NIH 5K08NS064168.
- Charcot-Marie-Tooth, type 1B
- Genetic variation
- Hereditary motor and sensory neuropathies
- Myelin protein zero
- Sequence homology