Clinical, neuroimaging and molecular characteristics of PPP2R5D-related neurodevelopmental disorders: an expanded series with functional characterisation and genotype-phenotype analysis.
J Med Genet
; 60(5): 511-522, 2023 05.
Article
em En
| MEDLINE
| ID: mdl-36216457
ABSTRACT
BACKGROUND:
Variants in PPP2R5D, affecting the regulatory B56δ subunit of protein phosphatase 2A (PP2A), have been identified in individuals with neurodevelopmental abnormalities. However, the molecular and clinical spectra remain incompletely understood.METHODS:
Individuals with PPP2R5D variants were enrolled through Simons Variation in Individuals Project/Simons Searchlight. Data were collected from medical history interviews, medical record review, online validated instruments and neuroimaging review. Genetic variants were biochemically characterised.RESULTS:
We studied 76 individuals with PPP2R5D variants, including 68 with pathogenic de novo variants, four with a variant of uncertain significance (VUS) and four siblings with a novel dominantly inherited pathogenic variant. Among 13 pathogenic variants, eight were novel and two (p.Glu198Lys and p.Glu200Lys) were highly recurrent. Functional analysis revealed impaired PP2A A/C-subunit binding, decreased short linear interaction motif-dependent substrate binding or both-with the most severe phenotypes associated with variants that completely retained one of these binding characteristics and lost the other-further supporting a dominant-negative disease mechanism. p.Glu198Lys showed the highest C-binding defect and a more severe clinical phenotype. The inherited p.Glu197Gly variant had a mild substrate binding defect, and three of four VUS had no biochemical impact. Common clinical phenotypes were language, intellectual or learning disabilities (80.6%), hypotonia (75.0%), macrocephaly (66.7%), seizures (45.8%) and autism spectrum disorder (26.4%). The mean composite Vineland score was 59.8, and most participants were in the 'moderate to low' and 'low' adaptive levels in all domains.CONCLUSION:
Our study delineates the most common features of PPP2R5D-related neurodevelopmental disorders, expands the clinical and molecular spectrum and identifies genotype-phenotype correlations.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transtornos do Neurodesenvolvimento
/
Deficiência Intelectual
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Med Genet
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos