Albarry Maan Abdullah, Latif Muhammad, Alreheli Ahdab Qasem, Awadh Mohammed A, Almatrafi Ahmad M, Albalawi Alia M, Basit Sulman
Department of Ophthalmology, College of Medicine, Taibah University, Almadinah, Saudi Arabia.
Center for Genetics and Inherited Diseases, Taibah University, Almadinah, Saudi Arabia.
PLoS One. 2021 Feb 11;16(2):e0246607. doi: 10.1371/journal.pone.0246607. eCollection 2021.
Waardenburg syndrome (WS) is a hereditary disorder affecting the auditory system and pigmentation of hair, eyes, and skin. Different variants of the disease exist with the involvement of mutation in six genes. The aim of the study is to identify the genetic defects underlying Waardenburg syndrome in a large family with multiple affected individuals. Here, in this study, we recruited a large family with eleven affected individuals segregating WS type 2. We performed whole genome SNP genotyping, whole exome sequencing and segregation analysis using Sanger approach. Whole genome SNP genotyping, whole exome sequencing followed by Sanger validation of variants of interest identified a novel single nucleotide deletion mutation (c.965delA) in the MITF gene. Moreover, a rare heterozygous, missense damaging variant (c.101T>G; p.Val34Gly) in the C2orf74 has also been identified. The C2orf74 is an uncharacterized gene present in the linked region detected by DominantMapper. Variants in MITF and C2orf74 follows autosomal dominant segregation with the phenotype, however, the variant in C2orf74 is incompletely penetrant. We proposed a digenic inheritance of variants as an underlying cause of WS2 in this family.
瓦登伯革氏综合征(WS)是一种遗传性疾病,会影响听觉系统以及头发、眼睛和皮肤的色素沉着。该疾病存在不同变体,涉及六个基因的突变。本研究的目的是在一个有多个患病个体的大家庭中确定瓦登伯革氏综合征的潜在基因缺陷。在此研究中,我们招募了一个有11名患病个体的大家庭,这些个体患有2型WS。我们进行了全基因组SNP基因分型、全外显子组测序,并使用桑格法进行分离分析。全基因组SNP基因分型、全外显子组测序,随后对感兴趣的变体进行桑格验证,在MITF基因中发现了一种新的单核苷酸缺失突变(c.965delA)。此外,还在C2orf74中鉴定出一种罕见的杂合错义有害变体(c.101T>G;p.Val34Gly)。C2orf74是一个未被表征的基因,存在于由DominantMapper检测到的连锁区域中。MITF和C2orf74中的变体与表型遵循常染色体显性分离,然而,C2orf74中的变体具有不完全外显率。我们提出双基因遗传变体是这个家族中WS2的潜在病因。