ABSTRACT
Clinicians who choose to prescribe a particular medication based on a family history of positive results are practicing a simple form of pharmacogenetics. Pharmacogenetics is the study of genetic variability in medication response (1). Pharmacogenetics had its formal beginnings in the 1950s when clinicians noted increased patterns of adverse reactions within certain families or ethnic groups. One example pertinent to psychiatry was the discovery that some patients receiving electroconvulsive therapy developed prolonged muscular paralysis after administration of succinylcholine due to a mutation within the gene coding for the enzyme succinylcholine esterase (2). Other early pharmacogenetic findings included attribution of peripheral neuropathy to slow acetylation of isoniazid in patients with tuberculosis, and hemolysis to glucose-6-phosphate deficiency in African-American males treated for malaria (1). The molecular genetic causes for these inherited differences were subsequently elucidated in the 1980s (3).
