wieviel kostet ein dna test — what are common causes?

Your question about the cost of a DNA test and 'common causes' is ambiguous. The provided context (pharmacogenetics, CRP, hormone tests, longevity) contains no pricing information and no clear definition of 'causes'. DNA test costs range from about €50 for basic ancestry to several hundred euros for comprehensive health or pharmacogenetic panels. 'Common causes' might refer to genetic variants underlying traits or disease risks, but the evidence for many consumer SNPs is weak to moderate. For example, FOXO3 variants have small, ancestry-specific effects on longevity, and FUT3 variants only mechanistically influence infection susceptibility. Without specifying the test type or the intended outcome, any answer remains speculative. I recommend clarifying whether you mean common reasons for testing (ancestry, nutrition, medication response) or common genetic causes of a particular condition. Only then can a meaningful, evidence-aware assessment be given.