Novel AHDC1 Gene Mutation in a Brazilian Individual: Implications of Xia-Gibbs Syndrome

Augusto C Cardoso-Dos-Santos; Thiago Oliveira Silva; Anderson Silveira Faccini; Thayne Woycinck Kowalski; Aida Bertoli-Avella; Jonas A Morales Saute; Lavinia Schuler-Faccini; Fabiano de Oliveira Poswar

doi:10.1159/000505843

Novel AHDC1 Gene Mutation in a Brazilian Individual: Implications of Xia-Gibbs Syndrome

Mol Syndromol. 2020 Feb;11(1):24-29. doi: 10.1159/000505843. Epub 2020 Feb 1.

Authors

Augusto C Cardoso-Dos-Santos¹, Thiago Oliveira Silva², Anderson Silveira Faccini¹, Thayne Woycinck Kowalski¹, Aida Bertoli-Avella³, Jonas A Morales Saute^{2

4}, Lavinia Schuler-Faccini^{1

2}, Fabiano de Oliveira Poswar²

Affiliations

¹ Genetics Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
² Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
³ CENTOGENE, AG, Rostock, Germany.
⁴ Internal Medicine Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.

Abstract

Xia-Gibbs syndrome (XGS) is a rare neurological disorder characterized by global developmental delay, hypotonia, intellectual disability, seizures, and sleep apnea. XGS is defined by monoallelic pathogenic variants in AHDC1. In this study, we identified a Brazilian patient carrying a likely de novo AHDC1 nonsense mutation (c.451C>T; p.Arg151*) which was absent in both parents. All disease-causative variants already associated with XGS have been reviewed and the mutation described here corresponds to the closest one to the N-terminal region. Our findings were discussed based on the suggested genotype-phenotype correlation of the disease.

Keywords: Exome sequencing; Intellectual disability; Neurodevelopmental disorders; Novel mutation; Sanger sequencing.