Definition: laboratory studies of blood or other tissue for the purpose of identifying genetic disorders. Relatively large chromosomal abnormalities such as deletion or transposition are identified by karyotyping (microscopic examination of chromosomes from a cell undergoing mitosis). More subtle aberrations can be detected by DNA probes (fabricated lengths of single-stranded DNA that match parts of the known gene). Genetic testing in the broadest sense includes biochemical testing for abnormal substances, or abnormally high or low concentrations of normal substances, which serve as markers of genetic deficiency or abnormality.
Synonym(s): deoxyribonucleic acid diagnostics