Genetic Techniques in Public Health

Genetic tests include the analysis of human DNA, RNA, chromosomes, proteins, and certain metabolites to detect a person's genotype for clinical purposes, including predicting the risk of disease, identifying gene mutation carriers, and establishing prenatal and clinical diagnoses or prognoses. Successful implementation of genetic tests to improve public health requires careful assessment of how and when genetic tests can and should be used to promote health and diagnose and prevent disease. This assessment must include the development of standards and guidelines for assuring quality genetic testing, and the consideration of ethical and legal issues.

Genetic tests need to be evaluated on the basis of several parameters before they can be taken from research laboratory to clinic. It is necessary to assess (1) how good the test is in predicting the underlying genotype, (2) how good the test is in diagnosing or predicting the phenotype or disease, and (3) the benefits and risks of the genetic test and ensuing interventions. Genetic test validity is quantified in terms of sensitivity (the probability of testing positive for the genetic test if there is a gene mutation or if disease occurs), specificity (the probability of testing negative if the genetic mutation is not present or if the disease does not occur), and predictive value (the test's ability to accurately predict disease).

All clinical laboratories in the United States that provide information to referring physicians are certified under the Clinical Laboratory Improvement Act (CLIA) amendments of 1988. The CLIA standards for quality control, proficiency testing, personnel, and other quality assurance practices apply to all genetic tests.