A Big Data Perspective on the Genomics of Hearing Loss

The completion of the human genome, the most fundamental example of big data in science and medicine, is the remarkable product of multidisciplinary collaboration and is regarded as one of the largest and most successful undertakings in human history. Unravelling the human genome means not only identifying the sequence of its more than 3.2 billion nucleotide bases, but also understanding disease-associated variations and applying this knowledge to patient-tailored precision medicine approaches. Genomics has moved at a remarkable pace, with much of the propelling forces behind this credited to technological developments in sequencing, computing, and bioinformatics, that have given rise to the term "big genomics data." The analysis of genetics data in a disease context involves the use of several big data resources that take the form of clinical genetics data repositories, in silico prediction tools, and allele frequency databases. These exceptional developments have cultivated high-throughput sequencing technologies that are capable of producing affordable high-quality data ranging from targeted gene panels to exomes and genomes. These new advancements have revolutionized the diagnostic paradigm of hereditary diseases including genetic hearing loss.Dissecting hereditary hearing loss is exceptionally challenging due to extensive genetic and clinical heterogeneity. There are presently over 150 genes involved in non-syndromic and common syndromic forms of hearing loss. The mutational spectrum of a single hearing loss associated-gene can have several tens to hundreds of pathogenic variants. Moreover, variant interpretation of novel variants can pose a challenge when conflicting information is deposited in valuable databases. Harnessing the power that comes from detailed and structured phenotypic information has proven promising for some forms of hearing loss, but may not be possible for all genetic forms due to highly variable clinical presentations. New knowledge in both diagnostic and scientific realms continues to rapidly accumulate. This overwhelming amount of information represents an increasing challenge for medical specialists. As a result, specialist medical care may evolve to take on new tasks and facilitate the interface between the human genetic diagnostic laboratory and the patient. These tasks include genetic counselling and the inclusion of genetics results in patient care.This overview is intended to serve as a reference to otolaryngologists who wish to gain an introduction to the molecular genetics of hearing loss. Key concepts of molecular genetic diagnostics will be presented. The complex processes underlying the identification and interpretation of genetic variants in particular would be inconceivable without the enormous amount of data available. In this respect, "big data" is an indispensable prerequisite for filtering genetic data in specific individual cases and making it clear and useful, especially for clinicians in contact with patients.