Definition of Pelizaeus-Merzbacher-like disease

Pelizaeus-Merzbacher-like disease: A disease that is virtually identical to Pelizaeus-Merzbacher disease (PMD) but without a mutation in the PLP1 gene that causes PMD. Both PMD and Pelizaeus-Merzbacher-like disease (PMLD) are characterized by rapid, involuntary movements of the eye (nystagmus), impaired motor development, ataxia, and difficulty articulating. Some patients with PMLD have diverse mutations in a gene called GJP12 which encodes the gap junction protein 12 (also known as connexin 46.6) that plays a key role in central myelination and is involved in peripheral myelination.