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Gene panels forClinical Areas

Clinical AreaOtorhinolaryngology

Notes on the clinical area

Here you will find the disease-related gene panels available for the clinical area specified above.

If you cannot find the disease you are looking for, please use a known synonym in the search (also in English).

Ear-Nose-Throat (ENT) diseases

Molecular genetic diagnostics are used to clarify the hereditary causes of ear, nose and throat diseases. The aim here is to identify deviations from the reference genome ("wild type") and then, if necessary, to distinguish between neutral variants and pathogenic mutations that are important for the physiological development and undisturbed functioning of the organism. The inheritance patterns of genetic diseases are the basis of genetic counselling for patients, persons at risk and affected families.

In the last 30 years, several thousand genes have been characterised which cause hereditary disorders or contribute to development. Current results of genetic research have a direct impact on the diagnostic procedure in the laboratory and in education and counselling. For example, mutations in independent genes on different chromosomes can cause clinically hardly differentiable hereditary disorders ("locus heterogeneity"). On the other hand, different mutations in one and the same gene can cause distinct disease patterns ("allelic heterogeneity"). Formal genetically and etiologically, the following groups of genetic diseases can be distinguished:

  • monogenic diseases (autosomal or X-linked inheritance)
  • digenic hereditary diseases, which only manifest themselves when mutations are simultaneously present in heterozygous state in two different genes. The two normal gene products together form functional heterodimers. Digenic inheritance affects ~3% of hereditary diseases in addition to the classic autosomal and X-linked diseases.
  • mitochondrial diseases (maternal or autosomal inheritance)
  • multifactorial diseases (interaction of several to many genes plus environmental factors)

Congenital malformations in the ENT area often appear sporadically - is there a genetic (co-)cause? Numerous ENT disorders are demonstrably based on genetic changes and lead to disorders in the proteins that build up the corresponding anatomical structures. DNA diagnostics therefore often comprises a step-by-step procedure in which the most frequent mutations are first tested before the very rare genetic causes are also identified in parallel approaches using extensive and cost-intensive panel procedures. Mutations found or all variants with unclear significance (VUS) are verified by DNA sequence analysis using Sanger technology. In the following some of the more common hereditary disease groups in ENT are listed.

Congenital syndromes and malformations

For some syndromes of the oculo-auriculo-vertebral spectrum (hemifacial microsomia) and the Goldenhar syndrome there are at present no direct DNA diagnostic possibilities yet. On the other hand, Treacher-Collins and Franceschetti syndrome can be elucidated by molecular genetics and separated from other similar malformations (Nager, Miller syndrome) by differential diagnostics.

Hereditary hearing disorders

One in 600 children hears poorly or is even deaf at birth. Between the ages of 60 and 70 years, 2.5% of the population has severe hearing loss. The genetic classification of hearing disorders typically distinguishes between syndromal and non-syndromal forms. In syndromal forms, there are other anomalies of other organ systems in addition to the hearing disorder, e.g. additional retinal degeneration (retinitis pigmentosa) in "Usher syndrome". Several hundred very complex syndromes are known. Among the non-syndromal hearing disorders, sensorineural hearing loss is the most prominent. Certain subtypes of Usher syndrome (hearing impairment, retinitis pigmentosa and possibly impaired balance) are inherited in digenic mode. Interestingly, even a family with a Y-chromosomal inherited form of a progressive hearing disorder has been described, although no gene on the Y-chromosome is causally mutated, but only chromosomally rearranged. Mutations in well over 200 different genes are probably responsible for the development of non-syndromal hearing disorders. Accordingly, different gene panels are available depending on the inheritance etc.

Disorders of olfactory perception

Isolated congenital anosmia is inherited in an autosomal dominant manner, the mutated gene is still unknown. In contrast, there are more than two dozen forms of hypogonadotropic hypogonadism with or without anosmia (Kallmann syndrome) for which different altered genes are precisely defined.

Hereditary ENT tumor diseases

The term head and neck tumours covers various types of cancer that occur in the head and neck region. These include malignant tumours of the oral cavity (carcinoma of the oral cavity), the throat (pharyngeal carcinoma), the larynx (laryngeal carcinoma), the nose, the paranasal sinuses and the outer neck, especially the thyroid gland. The classification is based mainly on pathological anatomical assessment and exact localization (oropharynx, tongue, nasopharynx, hypopharynx, larynx, trachea, parapharyngeal space etc., salivary glands, odontogenous and maxillofacial bone tumors, tumors of the external auditory canal, middle and inner ear, paragangliomas). Only for a few of these tumor entities are triggering gene mutations (e.g. paragangliomas) or susceptibility genes or specific somatic changes known (e.g. squamous squamous cell carcinoma of the esophagus).