Gentests

Gentests are laboratory procedures that analyze DNA, RNA, or chromosomes to identify genetic variations that may influence health, development, ancestry, or drug response. They are used in clinical, research, and consumer contexts to detect inherited conditions, assess disease risk, determine carrier status for recessive disorders, guide treatment choices through pharmacogenomics, and provide information about ancestry or paternity.

Common methods include targeted gene panels, whole-exome sequencing, and whole-genome sequencing, as well as genotyping arrays and copy number variant analysis. Samples are typically collected from blood or saliva, but other tissues can be used. Results are interpreted by specialists and reported according to established criteria, classifying variants as pathogenic, likely pathogenic, variants of uncertain significance, or benign. Clinically actionable findings are sought to inform medical management, while uncertain results may require periodic reevaluation as knowledge advances.

Applications span diagnostic testing for rare diseases, predictive or pre-symptomatic testing for individuals with a family history, carrier screening for reproductive planning, newborn screening in some programs, and pharmacogenetic testing to anticipate drug efficacy or risk of adverse effects. Direct-to-consumer tests offer genetic information outside traditional healthcare channels, though clinical interpretation often relies on professional guidance.

Limitations include incomplete penetrance, variable expressivity, and the possibility of inconclusive results. Privacy, data security, and potential genetic discrimination are important ethical and legal considerations. Regulation varies by country, with many regions requiring accredited laboratories and informed consent, and professional organizations providing guidelines for result interpretation and genetic counseling.