학술논문

Further delineation of the clinical spectrum of KAT6B disorders and allelic series of pathogenic variants
Document Type
Original Paper
Source
Genetics in Medicine: Official journal of the American College of Medical Genetics and Genomics. 22(8):1338-1347
Subject
KAT6B
KAT6B disorders
genitopatellar syndrome
Say–Barber–Biesecker–Young–Simpson syndrome
SBBYSS
Language
English
ISSN
1098-3600
1530-0366
Abstract
Purpose: Genitopatellar syndrome and Say–Barber–Biesecker–Young–Simpson syndrome are caused by variants in the KAT6B gene and are part of a broad clinical spectrum called KAT6B disorders, whose variable expressivity is increasingly being recognized.Methods: We herein present the phenotypes of 32 previously unreported individuals with a molecularly confirmed diagnosis of a KAT6B disorder, report 24 new pathogenic KAT6B variants, and review phenotypic information available on all published individuals with this condition. We also suggest a classification of clinical subtypes within the KAT6B disorder spectrum.Results: We demonstrate that cerebral anomalies, optic nerve hypoplasia, neurobehavioral difficulties, and distal limb anomalies other than long thumbs and great toes, such as polydactyly, are more frequently observed than initially reported. Intestinal malrotation and its serious consequences can be present in affected individuals. Additionally, we identified four children with Pierre Robin sequence, four individuals who had increased nuchal translucency/cystic hygroma prenatally, and two fetuses with severe renal anomalies leading to renal failure. We also report an individual in which a pathogenic variant was inherited from a mildly affected parent.Conclusion: Our work provides a comprehensive review and expansion of the genotypic and phenotypic spectrum of KAT6B disorders that will assist clinicians in the assessment, counseling, and management of affected individuals.