Novel mutation in CNTNAP1 results in congenital hypomyelinating neuropathy

Congenital hypomyelinating neuropathy (CHN) is a rare congenital neuropathy that presents in the neonatal period and has been linked previously to mutations in several genes associated with myelination. A recent study has linked 4 homozygous frameshift mutations in the contactin-associated protein 1 (CNTNAP1) gene with this condition.

We report a neonate with CHN who was found to have absent sensory nerve and compound muscle action potentials and hypomyelination on nerve biopsy.

On whole exome sequencing, we identified a novel CNTNAP1 homozygous missense mutation (p.Arg388Pro) in the proband, and both parents were carriers. Molecular modeling suggests that this variant disrupts a β-strand to cause an unstable structure and likely significant changes in protein function.

This report links a missense CNTNAP1 variant to the disease phenotype previously associated only with frameshift mutations. Muscle Nerve 55: 761-765, 2017.