Truncating Variants in NAA15 Are Associated with Variable Levels of Intellectual Disability, Autism Spectrum Disorder, and Congenital Anomalies.
Am J Hum Genet. 2018 Apr 09;:
Authors: Cheng H, Dharmadhikari AV, Varland S, Ma N, Domingo D, Kleyner R, Rope AF, Yoon M, Stray-Pedersen A, Posey JE, Crews SR, Eldomery MK, Akdemir ZC, Lewis AM, Sutton VR, Rosenfeld JA, Conboy E, Agre K, Xia F, Walkiewicz M, Longoni M, High FA, van Slegtenhorst MA, Mancini GMS, Finnila CR, van Haeringen A, den Hollander N, Ruivenkamp C, Naidu S, Mahida S, Palmer EE, Murray L, Lim D, Jayakar P, Parker MJ, Giusto S, Stracuzzi E, Romano C, Beighley JS, Bernier RA, Küry S, Nizon M, Corbett MA, Shaw M, Gardner A, Barnett C, Armstrong R, Kassahn KS, Van Dijck A, Vandeweyer G, Kleefstra T, Schieving J, Jongmans MJ, de Vries BBA, Pfundt R, Kerr B, Rojas SK, Boycott KM, Person R, Willaert R, Eichler EE, Kooy RF, Yang Y, Wu JC, Lupski JR, Arnesen T, Cooper GM, Chung WK, Gecz J, Stessman HAF, Meng L, Lyon GJ
N-alpha-acetylation is a common co-translational protein modification that is essential for normal cell function in humans. We previously identified the genetic basis of an X-linked infantile lethal Mendelian disorder involving a c.109T>C (p.Ser37Pro) missense variant in NAA10, which encodes the catalytic subunit of the N-terminal acetyltransferase A (NatA) complex. The auxiliary subunit of the NatA complex, NAA15, is the dimeric binding partner for NAA10. Through a genotype-first approach with whole-exome or genome sequencing (WES/WGS) and targeted sequencing analysis, we identified and phenotypically characterized 38 individuals from 33 unrelated families with 25 different de novo or inherited, dominantly acting likely gene disrupting (LGD) variants in NAA15. Clinical features of affected individuals with LGD variants in NAA15 include variable levels of intellectual disability, delayed speech and motor milestones, and autism spectrum disorder. Additionally, mild craniofacial dysmorphology, congenital cardiac anomalies, and seizures are present in some subjects. RNA analysis in cell lines from two individuals showed degradation of the transcripts with LGD variants, probably as a result of nonsense-mediated decay. Functional assays in yeast confirmed a deleterious effect for two of the LGD variants in NAA15. Further supporting a mechanism of haploinsufficiency, individuals with copy-number variant (CNV) deletions involving NAA15 and surrounding genes can present with mild intellectual disability, mild dysmorphic features, motor delays, and decreased growth. We propose that defects in NatA-mediated N-terminal acetylation (NTA) lead to variable levels of neurodevelopmental disorders in humans, supporting the importance of the NatA complex in normal human development.
PMID: 29656860 [PubMed – as supplied by publisher]