title: Identification of 2 Potentially Relevant Gene Mutations Involved in Strabismus Using Whole-Exome Sequencing.
abstract: BACKGROUND The etiology of strabismus has a genetic component. Our study aimed to localize the candidate causative gene mutant in a Chinese family with strabismus and to describe its underlying etiology. MATERIAL AND METHODS Genomic DNA was extracted from the affected individual and his parents in a Chinese pedigree with strabismus. The resulting exomes were sequenced by whole-exome sequencing. After variant calling and filtering, the candidate causative gene mutations were selected for the rarity and predicted damaging effect, which complied with the model of recessive disease transmission. RESULTS We examined a Chinese strabismus pedigree with the parents unaffected and 2 offspring affected. Whole-exome sequencing and bioinformatics filtering identified 2 variants including Abelson helper integration site 1 (AHI1) gene and nebulin (NEB) gene. The variant in the AHI1 gene, c.A3257G (p.E1086G), and the altered amino acid had a damaging effect on the encoded protein predicted by Polyphen2. Moreover, this change was located in the conserved SH3 domain of AHI1. Biallelic pathogenic variant in AHI1 gene can cause Joubert syndrome-related disorders with oculomotor apraxia characteristics. Additionally, c.A914G mutation was found in nebulin (NEB) gene. Therefore, we concluded that AHI1 c.3257A>G and NEB c.914 A>G were potential causal variants in this strabismus pedigree. CONCLUSIONS We detected an AHI1 homozygous mutation in the affected individual. Whole-exome sequencing is a powerful way to identify causally relevant genes, improving the understanding of this disorder.
authors.affiliation: Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland).|Department of Ophthalmology, Jining No. 1 People's Hospital, Jining, Shandong, China (mainland).
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Min
authors.affiliation: Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland).
authors.forename: Haiying
authors.initials: H
authors.lastname: Fan
authors.affiliation: Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland).
authors.forename: Guiqiu
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland).
authors.forename: Guixiang
authors.initials: G
authors.lastname: Liu
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics* / Q000378:metabolism; D033942:Adaptor Proteins, Vesicular Transport; D000293:Adolescent; D000328:Adult; D002531:Cerebellum / Q000002:abnormalities / Q000378:metabolism; D004252:DNA Mutational Analysis / Q000379:methods; D059472:Exome; D005124:Eye Abnormalities / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000235:genetics / Q000378:metabolism; D008297:Male; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010375:Pedigree; D012160:Retina / Q000002:abnormalities / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013285:Strabismus / Q000235:genetics* / Q000378:metabolism
chemical_list: C487178:AHI1 protein, human; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D009124:Muscle Proteins; C035620:nebulin