Phenotype and genotype of deaf patients with combined genomic and mitochondrial inheritance models

Mitochondrion. 2013 Nov;13(6):791-4. doi: 10.1016/j.mito.2013.05.004. Epub 2013 May 18.

Abstract

In most studies, sensorineural hearing loss is reported as a single-gene disease with autosomal dominant or autosomal recessive or with X-linked or maternal inheritance. It is uncommon that the hearing impairment is caused by a combined inheritance model including genomic and mitochondrial models. Here, we report six patients with sensorineural hearing loss caused by co-existing mutations in GJB2 or SLC26A4 and the mitochondrial gene. And there was no significant difference in hearing phenotypes between the six patients and the controls. The results indicate the complicated genetic etiology of, and may impact the diagnostic strategy for, hereditary hearing impairment. All patient siblings will carry mitochondrial DNA A1555G or C1494T mutations, and 25% of siblings may carry the same homozygous or compound heterozygote mutations in GJB2 or SLC26A4. Although this combined inheritance is not common in the Chinese deaf population (0.10%), our findings will have great impact in genetic counseling and risk prediction for deafness.

Keywords: Autosomal recessive; Different genes; Genetic model; Maternal inheritance; Sensorineural hearing loss.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cohort Studies
  • Connexin 26
  • Connexins
  • Deafness / genetics*
  • Female
  • Genome, Mitochondrial*
  • Genotype
  • Humans
  • Male
  • Models, Genetic*
  • Pedigree
  • Phenotype

Substances

  • Connexins
  • GJB2 protein, human
  • Connexin 26