Allele‐specific polymerase chain reaction for the detection of single nucleotide polymorphism in amlodipine‐induced gingival enlargement

Summary What is known and objective Studies indicate that there is an increased serum concentration of amlodipine (a calcium channel blocker used to treat hypertension and angina) in patients having mutant multidrug resistance 1 (MDR1) gene. Hence, genetic factors may play a very significant role in amlodipine‐induced complications including gingival enlargement. Case description Three patients with amlodipine‐induced gingival enlargement showed improvement following drug substitution of amlodipine with enalapril (an angiotensin‐converting enzyme inhibitor) and non‐invasive periodontal therapy. Using allele‐specific polymerase chain reaction, single nucleotide polymorphism of MDR1 gene of heterozygous mutant type (CT genotype) was identified in all three cases. What is new and conclusion Drug‐induced complications can potentially be a result of genetic factors, in combination with various local and systemic factors. Identifying genetic polymorphisms early might help predict adverse reactions and determine prognosis. Three patients with amlodipine induced gingival enlargement showed mutation in MDR1 gene. Simple drug substitution and non‐invasive periodontal therapy resolved the condition in all three patients.