Variants in the zinc transporter TMEM163 cause a hypomyelinating leukodystrophy.
Brain
; 145(12): 4202-4209, 2022 12 19.
Article
em En
| MEDLINE
| ID: mdl-35953447
ABSTRACT
Hypomyelinating leukodystrophies comprise a subclass of genetic disorders with deficient myelination of the CNS white matter. Here we report four unrelated families with a hypomyelinating leukodystrophy phenotype harbouring variants in TMEM163 (NM_030923.5). The initial clinical presentation resembled Pelizaeus-Merzbacher disease with congenital nystagmus, hypotonia, delayed global development and neuroimaging findings suggestive of significant and diffuse hypomyelination. Genomic testing identified three distinct heterozygous missense variants in TMEM163 with two unrelated individuals sharing the same de novo variant. TMEM163 is highly expressed in the CNS particularly in newly myelinating oligodendrocytes and was recently revealed to function as a zinc efflux transporter. All the variants identified lie in highly conserved residues in the cytoplasmic domain of the protein, and functional in vitro analysis of the mutant protein demonstrated significant impairment in the ability to efflux zinc out of the cell. Expression of the mutant proteins in an oligodendroglial cell line resulted in substantially reduced mRNA expression of key myelin genes, reduced branching and increased cell death. Our findings indicate that variants in TMEM163 cause a hypomyelinating leukodystrophy and uncover a novel role for zinc homeostasis in oligodendrocyte development and myelin formation.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doença de Pelizaeus-Merzbacher
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Brain
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Índia