The congenital form has similar characteristics but presents early in infancy and features rapid disease progression. Transitional and adult subtypes have a later onset and less severe symptomatology. [hon.ch]

Patients may present with pendular eye movements (nystagmus) hypotonia pyramidal disease ataxia Genetics Pelizaeus-Merzbacher disease is the result of abnormalities of the proteolipidprotein (PLP1) gene locus at Xq22. [radiopaedia.org]

Elucidation of the pathogenic mechanism and potential treatment strategy for a female patient with spastic paraplegia derived from a single-nucleotide deletion in PLP1. J Hum Genet. 2019;64:665-671. Margraf RL, et al. [rarediseases.org]

Etiology One PMLD form is due to mutations in the GJC2gene encoding the gap junction protein C2. There are very likely other PMLD forms that have not been defined but that are caused by mutations affecting other genes involved in myelination. [rarediseases.info.nih.gov]

Epidemiology Prevalence is unknown. Clinical description It is characterized by early-onset nystagmus, delayed motor milestones, progressive spasticity, ataxia, and diffuse leukodystrophy on MRI. [rarediseases.info.nih.gov]