Hearing loss is the most common birth defect in developed countries. One in every 500 newborns has permanent and bilateral sensorineural hearing loss, and in adolescence the prevalence increases to 3.5 in every 1,000 people. More than 50% of deafness that occurs in children before the onset of speech has a genetic cause, most often autosomal recessive and without association with any other medical problem.

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For this autosomal recessive nonsyndromic hearing loss, more than half of the cases are the result of a single mutation in the gene GJB2 (connexin 26) or GJB6 (connection 30) 2. The carrier rate in the general population for the Pathological variant of GJB2 is approximately 1 in 33. In addition to the autosomal recessive inheritance of the causal genetic variants (around 70% of cases of genetic hearing loss in total), heredity can also be autosomal dominant (15%), X-linked or mitochondrial3.

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Deafness can occur as part of a syndrome, for example the Usher, Pendred, Jervell and Lange-Nielsen and Waardenburg syndromes. The selective approach of our genetic testing panels allows the simultaneous detection of dozens of genes known to cause non-syndromic hearing loss with autosomal recessive or dominant inheritance, as well as deafness syndromes that may occur as isolated hearing loss.