Objective: To determine if dopamine (D3) receptor genotypes are associated with anovulation and response to ovulation induction with clomiphene citrate.
Design: Clinical and laboratory characteristics of anovulatory patients and ovulatory controls were compared with findings at the DNA level.
Setting: An outpatient clinic at an university medical center.
Patients: One hundred eighty human Hispanic female volunteers (130 of these with documented ovulatory status) were studied.
Interventions: Genomic DNAs were extracted from each patient. Polymerase chain reaction with subsequent restriction digest was performed to analyze the D3 receptor allele status (two possible alleles).
Main outcome measures: Menstrual history, serum T, and midluteal serum Ps from spontaneous and clomiphene cycles were correlated with D3 receptor genotype.
Results: Hispanic females with the 22 genotype compared with the other genotypes (11 and 12) were more likely to have irregular menses, an elevated serum T (> or = 70 ng/dL [conversion factor to SI unit, 3.467]), and hyperandrogenic chronic anovulation. These patients tended to be resistant to ovulation induction requiring a significantly higher dose of clomiphene to achieve an ovulatory response (22 genotype [mean +/- SEM] [140.0 +/- 19.0 mg] versus 11 [77.1 +/- 17.5 mg] or 12 [69.2 +/- 13.1 mg]). This effect was independent of patient age, weight, or serum T level.
Conclusions: Hyperandrogenic chronic anovulation may have a genetic component. Genetic analysis may be useful in predicting resistance to ovulation induction with clomiphene.