Hereditary hearing disorders

Hearing disorders are the most common sensory deficit in humans. Approximately 1/500 newborns is affected, usually due to a genetic cause. Pathogenic variants in more than 100 genes are known, and many more are suspected. Furthermore, there are many genetic hearing disorders which do not manifest until adulthood.

Genetic counselling of the parents is essential, and molecular genetic analyses may clarify whether the hearing disorder is isolated or syndromic. About 30% of children with an apparent isolated hearing disorder have a syndrome. The most common syndrome is Usher syndrome, which manifests in about 10% of children with congenital hearing loss. They develop retinal degeneration in childhood or adolescence, which increasingly impairs their vision.

Other important deafness syndromes can affect kidneys, thyroid gland and heart. Based on the genetic diagnosis, regular checkups by specialists, other than the pediatric audiologist, can be planned accordingly. This is crucial for individualized medical follow-up/support/therapy.

Furthermore, a genetic diagnosis enables an estimation of the recurrence risk. Among other aspects, this can help with better preparation for the birth of another affected child. Last but not least, the proof of a genetic cause largely excludes exogenous reasons (e.g. infections).

In addition, intensive research is being done on therapeutic approaches, especially for syndromic forms (e.g. Usher syndrome). They are often gene-specific (especially gene replacement therapies for autosomal recessive forms), but in some cases also tailored to certain relatively common variants or mutation types.

Why Bioscientia?

Collaborations: We work closely with patient organizations and specialized university centers.

Diagnostics: We use the most modern methods of high-throughput sequencing and genomic structural analysis to uncover even complex causes of hereditary hearing disorders.

Research: We have been active in human genetic research on hereditary hearing disorders for more than 25 years and identified novel genes for isolated and syndromic hearing disorders (see below, Publications).

Links:

• Hereditary Hearing Loss Homepage, Overview of known hearing loss genes 

• German Society for Human Genetics, GfH, about our diagnostic and research focus

• Clinical studies

• Living with Usher syndrome e.V., LmU

Publications

• Identification of the CACNA1D gene for SANDD syndrome associated with cardiac arrhythmia; PMID: 21131953.
• Identification of the gene for Usher syndrome type 1D (USH1D); PMID: 11138009
• Identification of the gene for Usher syndrome type 2D (USH2D); PMID: 17171570
• Identification of the DFNB59 gene for autosomal recessive hearing impairment (DFNB59); PMID: 17301963
• Identification of the retinal modifier and digenic Usher syndrome gene PDZD7; PMID: 20440071
• Identification of the PTPRQ gene for autosomal dominant hearing impairment (DFNA73); PMID: 29309402
• Identification of the OSBPL2 gene for autosomal dominant hearing impairment (DFNA67); PMID: 25759012