Case Report: Christianson Syndrome Caused by SLC9A6 Mutation: From Case to Genotype-Phenotype Analysis

• DOI: 10.3389/fgene.2021.783841
• Publication Date: 2021-12-20T11:42:50Z
• Authors: Yueyun Lan; Sheng Yi; Mengting Li; Jinqiu Wang; Qi Yang; Shang Yi; Fei Chen; Limei Huang; Yiyan Ruan; Yiping Shen; Jingsi Luo; Zailong Qin
• Keywords: Microcephaly; Global developmental delay; Proband; Sanger sequencing; Neurodevelopmental disorder; Rett Syndrome; Speech delay

Christianson syndrome (CS) is an X-linked neurodevelopmental characterized by microcephaly, epilepsy, ataxia, and severe generalized developmental delay. Pathogenic mutations in the SLC9A6 gene, which encodes Na+/H+ exchanger protein member 6 (NHE6), are associated with CS autism spectrum disorder males. In this study, whole exome sequencing (WES) Sanger revealed a novel de novo frameshift variant c.1548_1549insT of 14-month-old boy early-onset seizures. According to The American College Medical Genetics Genomics (ACMG)/the Association for Molecular Pathology (AMP) guidelines, was classified as pathogenic. proband presented several core symptoms typical including motor delay, distal muscle weakness, micrognathia, occasional unprovoked laughter, swallowing speech difficulties. Electroencephalography (EEG) showed spikes-slow waves frontal pole, frontal, anterior temporal midline point areas. Gesell development schedules (GDS) indicated We also summarized all reported variants analyzed correlation genotype phenotype CS. Our study extends mutation it might imply that phenotypes not correlated genotypes.