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Gene panels for Clinical Areas

Clinical AreaRheumatology

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).

Rheumatology and genetics

Molecular genetic diagnostics are used to clarify the hereditary causes of thousands of genetically determined 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 function of bones and joints. The inheritance patterns of genetically determined diseases are the basis of genetic counselling for patients, persons at risk and affected families. Over the past 30 years, thousands of genes that cause hereditary diseases or contribute to the development of genetic disorders have been successively characterised. Current results of genetic research have a direct impact on the diagnostic procedure in the laboratory and in genetic counselling.

Formal genetics and etiology

Formal genetically and etiologically, the following groups of genetic diseases can be distinguished:

  • monogenic diseases (autosomal or X-chromosomal inheritance)
  • mitochondrial diseases (maternal or autosomal inheritance)
  • multifactorial diseases (interaction of several to many genes plus environmental factors) DNA diagnostics therefore often involves 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 comprehensive and more cost-intensive panel procedures. Mutations found or all variants with unclear significance (VUS) are verified by DNA sequence analysis using Sanger technology.

Morbus Bechterew

Exact causes of Bechterew disease are unknown, but autoimmunologically triggered inflammatory reactions can be assumed. A technically less complex DNA diagnosis is possible if M. Bechterew is suspected: There is no actual mutation causing the disease, but only a statistical association with the presence of the HLA-B27 allele. These alleles are detectable in 96% of Bechterew patients, yet in the healthy population only in 8%. In M. Bechterew, too, infections could have a pathogenic effect as well as extreme temperature effects and physical or mental stress, thus obviously multifactorial pathogenesis must be assumed.

Hemochromatoses

Hemochromatosis is caused by accumulation of iron with tissue damage, followed by systemic symptoms of liver disease, cardiomyopathy, diabetes - and joint disease. The diagnosis is initially based on altered HFE gene mutations. 70% of patients with homozygous C282Y mutations in the HFE gene show elevated ferritin levels, and 10% of these patients also show organ dysfunction. Hemochromatoses of type IIA (HJV mutations), IIB (HAMP), III (TFR2), IV (SLC40A1) and V (FTH1) are significantly less frequent. All genes of these subtypes are included in a combined panel, including the so-called modifier gene BMP2, which, for example, also regulates the penetrance of type 1 HFE.

Hormone disorders

Genetically caused hyperparathyroidism, hyperthyroidism and diabetes mellitus also lead to rheumatic diseases of the soft tissue. Respective gene panls have been established for differential diagnostic perusual.

Other multifactorial rheumatological diseases

Most common rheumatic diseases cannot be addressed with direct DNA diagnostics. Although hereditary involvement is sometimes obvious, this can only be proven experimentally at great expense. Many processes in muscle and soft tissues are involved in rheumatological events, but the contributions of individual genes are usually rather small. The suspected regions in the human genome are literally lost in the background noise of genetic differences, if not the samples are used from thousands and thousands of well characterized patients and healthy control persons.