Genetic Epilepsy

Gene: PLP1

Green List (high evidence)

PMID: 7512350 (1994) - Mouse study demonstrating that seizures and convulsions are a result of a 2-fold increased PLP gene dosage. (Cited in OMIM)

PMID: 11071483 (2000) - One family with 2x brothers affected with PMD, both developing seizures in late teens. Other symptoms in both brothers include hypotonia at birth, nystagmus, and slowly progressive spastic paraplegia. (Cited in OMIM)

PMID: 21679407 (2011) - Male cohort, 43 individuals from 38 unrelated families with a PLP1-related disorder diagnosis. Seizures present in 2/43 males (both PLP1 duplication mutations). Additional symptoms include 3/43 stridor, 4/43 developmental delay, and 18/43 muscular hypotonia.

PMID: 28133555 (2017) - Case report on 9 year old male affected with classic PMD. Presented with a history of seizures since age 4. Also presents with developmental delay, nystagmus, microcephaly, spastic quadriplegia. Maternally inherited gain of 436Kb on Xq22.2 encompassing TCEAL1,MORF4L2, PLP1, and RAB9B, of which only PLP1 is associated with a disease.

PMID: 29486744 (2018) - Case report on family diagnosed with connatal PMD (previously diagnosed as X-linked epileptic seizures). The PLP1 missense mutation p.Ala84Asp was found to segregate in the family. 1x proband presenting with daily generalised seizures, onset at 8 months and no treatment response. 2x cousins and 2x maternal uncles also presented with epilepsy, all onset around 6 months and all died in childhood. Additional symptoms include 5/5 hypotonia and 5/5 psycho-motor delay. Consanguinity reported in the family.

PMID: 35346287 (2022) - Chinese cohort of 141 patients, 111 whom were followed up with. Seizures present in 4/28 individuals with connatal PMD, including 1 patient who died due to epileptic seizures at age 7, and 4/56 individuals with transitional PMD. Additional symptoms include 111/111 development delay, 110/111 nystagmus, 93/111 hypotonia, 35/111 stridor, and 4/111 respiratory difficulty.

PMID: 37637647 (2023) - Case report on 1x newborn individual diagnosed with failure to thrive and later PMD. Presented with episodes of rapid eye and side-to-side head movement episodes of 5-10 seconds, onset one month after birth. Diagnosis of seizure disorder considered before further testing. Individual hemizygous for PLP1: c.67G>A (p.Gly23Arg), maternally inherited.

GeneReviews: Seizures may develop in infants affected by 'severe connatal PMD'.
Sources: Literature

Created: 4 Jan 2024, 6:53 a.m.

Mode of inheritance
X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)

Phenotypes
Pelizaeus-Merzbacher Disease, MIM#312080

Publications

• 7512350
• 11071483
• 21679407
• 28133555
• 29486744
• 35346287
• 37637647