Deafness, Autosomal Recessive 10

Alternative Names

  • DFNB10
Back to search Result
WHO-ICD-10 version:2010

Diseases of the ear and mastoid process

Other disorders of ear

OMIM Number

605316

Mode of Inheritance

Autosomal recessive

Gene Map Locus

21q22.3

Description

Congenital deafness is the most common sensory defect in human, with an incidence of about 1:1000 births. Approximately, 50% of congenital deafness has a genetic origin. Most cases of deafness are not accompanied by additional obvious abnormalities and are, therefore, considered to be non-syndromic. It is estimated that approximately 80% of inherited non-syndromic deafness is caused by autosomal recessive defects.

Molecular Genetics

More than 10 mutations in the TMPRSS3 gene have been found to cause DFNB10 non-syndromic congenital deafness. The TMPRSS3 gene encodes a protein that belongs to the serine protease family. Serine proteases are known to be involved in a variety of normal biological processes, including digestion, blood clotting, and inflammation. However, the exact physiological function of the protein encoded by the TMPRSS3 gene is unknown, but it appears to be essential for normal hearing. The protein likely plays a role in the development and maintenance of the inner ear, and is also present in many other tissues. Researchers believe that the TMPRSS3 protein activates a protein called the epithelial amiloride sensitive sodium channel (ENaC), which probably controls important chemical signaling pathways in the inner ear.

Epidemiology in the Arab World

View Map

Other Reports

Palestine

In a large, inbred Palestinian family with more than 40 non-hearing members, Bonne-Tamir et al. (1996) presented evidence for linkage between a locus for non-syndromic deafness, which they designated DFNB10, and several markers located near the telomere of chromosome 21q. Most of the affected members of this family resulted from consanguineous unions, indicating that they are homozygous for the same genetic defect. Homozygosity of marker alleles was evident for only the most telomeric of 3 linked markers, D21S1259, suggesting that DFNB10 is closest to this locus.

Scott et al. (2001) reported a Palestinian family with the congenital form of deafness designated DFNB10. They found that exon 11 of the TMPRSS3 gene contained a 1.7-kb product in affected members of the family instead of the 476-bp product amplified from normal controls. Eight affected individuals were homozygous for this product; 13 obligate carriers had one copy. Sequence analysis showed a complex rearrangement with deletion of 8 bp and insertion of 18 complete beta-satellite repeat monomers.

Walsh et al. (2006) undertook a study to identify the genes responsible for inherited hearing loss, by linkage scan using microsatellite markers in 156 affected individuals and their families. Walsh et al. (2006) were able to identify a mutation in the TMPRSS3 gene in a consanguineous Palestinian family with 10 living members diagnosed with prelingual, bilateral, severe to profound hearing loss, with thresholds poorer than 85 decibels (dB) at all frequencies. All affected members of the family were found to be homozygous for a frameshift mutation (988delA), while all unaffected members of the family were found to be either heterozygous carriers of this mutation or wild type. Three other hearing impaired Palestinian individuals, unrelated to this family, were also found to be homozygous for the mutation.

Shahin et al. (2010) reported a consanguineous Palestinian family in which all sibs (one male and two females) had prelingual bilateral autosomal recessive non-syndromic hearing loss (NSHL). Shahin et al. (2010) identified a nonsense mutation (c.783T>A; p.Cys194STOP) in the TMPRSS3 gene in affected members of this family.

Tunisia

Masmoudi et al. (2001) identified novel missense mutations in the TMPRSS3 gene in two unrelated consanguineous Tunisian families segregating congenital non-syndromic autosomal recessive sensorineural deafness (DFNB10). The audiometric tests showed a loss of hearing greater than 70 dB, in all affected individuals of both families. The first family was found to be homozygous for the p.W251C missense mutation, while the second family was found to be homozygous for a different missense mutation (p.P404L).

© CAGS 2024. All rights reserved.