Genetic testing is a medical investigation that analyzes DNA, RNA, chromosomes, or specific proteins to identify changes that may cause, contribute to, or indicate risk for a health condition. Samples are usually collected through blood, saliva, buccal swabs, or in some cases, amniotic fluid or chorionic villus tissue during pregnancy. The DNA is then processed in a laboratory and analyzed using specialized techniques ranging from single-gene analysis to whole genome sequencing.