Frameshift variant in MITF gene in a large family with Waardenburg syndrome type II and a co-segregation of a C2orf74 variant

PLoS One. 2021 Feb 11;16(2):e0246607. doi: 10.1371/journal.pone.0246607. eCollection 2021.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Chromosome Segregation
  • Exome Sequencing
  • Female
  • Frameshift Mutation*
  • Humans
  • Male
  • Microphthalmia-Associated Transcription Factor / genetics*
  • Mutation, Missense*
  • Open Reading Frames*
  • Pedigree
  • Polymorphism, Single Nucleotide
  • Waardenburg Syndrome / genetics*

Substances

  • MITF protein, human
  • Microphthalmia-Associated Transcription Factor

Supplementary concepts

  • Waardenburg syndrome type 2

Grants and funding

Ahmad M Almatrafi obtained funds under the research group grant number 10057 from the Deanship of Scientific Research (DSR), Taibah University Almadinah. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funds were used for purchase of reagents and chemicals.