Pelizaeus-Merzbacher disease
Pelizaeus-Merzbacher Disease is an X-linked, invariably fatal, leukodystrophy beginning either in early childhood or just after birth, and characterized by slowly progressive signs and symptoms resulting from widespread white matter dysfunction.
Patients present with pendular eye movements, hypotonia, choreoathetosis, and pyramidal signs early in the disease, followed later by spasticity, dementia, and ataxia.
The disease has been shown to arise in most cases from defects in a gene on the X chromosome that encodes proteolipid protein (PLP), a major protein of CNS myelin.
Although myelin is nearly completely lost in the cerebral hemispheres, patches may remain, giving a "tigroid" appearance to tissue sections stained for myelin.
Etiology
duplication or deletion of the proteolipid protein gene PLP1
References
Yool DA, Edgar JM, Montague P, Malcolm S. The proteolipid protein gene and myelin disorders in man and animal models. Hum Mol Genet. 2000 Apr 12;9(6):987-92. PMID: #10767322#
Woodward K, Malcolm S. Proteolipid protein gene: Pelizaeus-Merzbacher disease in humans and neurodegeneration in mice. Trends Genet. 1999 Apr;15(4):125-8. PMID: #10203813#