Brain monoamine vesicular transport disease caused by homozygous SLC18A2 variants: A study in 42 affected individuals.
Genet Med
; 25(1): 90-102, 2023 01.
Article
em En
| MEDLINE
| ID: mdl-36318270
ABSTRACT
PURPOSE:
Brain monoamine vesicular transport disease is an infantile-onset movement disorder that mimics cerebral palsy. In 2013, the homozygous SLC18A2 variant, p.Pro387Leu, was first reported as a cause of this rare disorder, and dopamine agonists were efficient for treating affected individuals from a single large family. To date, only 6 variants have been reported. In this study, we evaluated genotype-phenotype correlations in individuals with biallelic SLC18A2 variants.METHODS:
A total of 42 affected individuals with homozygous SLC18A2 variant alleles were identified. We evaluated genotype-phenotype correlations and the missense variants in the affected individuals based on the structural modeling of rat VMAT2 encoded by Slc18a2, with cytoplasm- and lumen-facing conformations. A Caenorhabditis elegans model was created for functional studies.RESULTS:
A total of 19 homozygous SLC18A2 variants, including 3 recurrent variants, were identified using exome sequencing. The affected individuals typically showed global developmental delay, hypotonia, dystonia, oculogyric crisis, and autonomic nervous system involvement (temperature dysregulation/sweating, hypersalivation, and gastrointestinal dysmotility). Among the 58 affected individuals described to date, 16 (28%) died before the age of 13 years. Of the 17 patients with p.Pro237His, 9 died, whereas all 14 patients with p.Pro387Leu survived. Although a dopamine agonist mildly improved the disease symptoms in 18 of 21 patients (86%), some affected individuals with p.Ile43Phe and p.Pro387Leu showed milder phenotypes and presented prolonged survival even without treatment. The C. elegans model showed behavioral abnormalities.CONCLUSION:
These data expand the phenotypic and genotypic spectra of SLC18A2-related disorders.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encefalopatias
/
Distonia
/
Transtornos dos Movimentos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Genet Med
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Japão