Delineating the Smith-Kingsmore syndrome phenotype: Investigation of 16 patients with the MTOR c.5395G > A p.(Glu1799Lys) missense variant.
Am J Med Genet A
; 185(8): 2445-2454, 2021 08.
Article
in En
| MEDLINE
| ID: mdl-34032352
ABSTRACT
Smith-Kingsmore Syndrome (SKS) is a rare genetic syndrome associated with megalencephaly, a variable intellectual disability, autism spectrum disorder, and MTOR gain of function variants. Only 30 patients with MTOR missense variants are published, including 14 (47%) with the MTOR c.5395G>A p.(Glu1799Lys) variant. Limited phenotypic data impacts the quality of information delivered to families and the robustness of interpretation of novel MTOR missense variation. This study aims to improve our understanding of the SKS phenotype through the investigation of 16 further patients with the MTOR c.5395G>A p.(Glu1799Lys) variant. Through the careful phenotypic evaluation of these 16 patients and integration with data from 14 previously reported patients, we have defined major (100% patients) and frequent (>15%) SKS clinical characteristics and, using these data, proposed guidance for evidence-based management. In addition, in the absence of functional studies, we suggest that the combination of the SKS major clinical features of megalencephaly (where the head circumference is at least 3SD) and an intellectual disability with a de novo MTOR missense variant (absent from population databases) should be considered diagnostic for SKS.
Key words
Full text:
1
Database:
MEDLINE
Main subject:
Phenotype
/
Mutation, Missense
/
Alleles
/
Genetic Association Studies
/
TOR Serine-Threonine Kinases
Type of study:
Diagnostic_studies
/
Guideline
/
Prognostic_studies
Limits:
Adolescent
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
Language:
En
Journal:
Am J Med Genet A
Journal subject:
GENETICA MEDICA
Year:
2021
Type:
Article
Affiliation country:
United kingdom