Common single nucleotide polymorphisms in intron 3 of the calpain-10 gene influence hirsutism

To study three common polymorphisms in intron 3 of the calpain-10 gene (CAPN10) in hyperandrogenic patients.

Case-control study.

Academic hospital.

Ninety-seven hyperandrogenic patients and 37 healthy controls.

Basal and adrenocorticotropin-stimulated serum samples and genomic DNA samples were obtained during the follicular phase of the menstrual cycle.

Genotyping of the UCSNP43, UCSNP44, and UCSNP45 polymorphisms in CAPN10 and serum androgen levels.

Sixteen patients had idiopathic hirsutism, defined as normal serum androgen levels and regular menstrual cycles. Eighty-one hyperandrogenic patients (those presenting with hyperandrogenemic hirsutism or the polycystic ovary syndrome) were analyzed further. UCSNP45 alleles were distributed differently among the study groups. Heterozygosity for the uncommon C allele was increased in patients with idiopathic hirsutism (31.3%) and reduced in hyperandrogenic patients (7.4%) compared with controls (16.2%). The UCSNP44 and UCSNP43 alleles were in linkage disequilibrium, and were distributed equally among patients with idiopathic hirsutism, hyperandrogenism, and controls. However, the uncommon A allele at UCSNP43 was associated with higher hirsutism score (mean [+/- SD], 9.9 +/- 6.8, 12.7 +/- 7.7, and 14.6 +/- 8.2 in GG, GA, and AA participants, respectively). No other differences were observed in clinical and biochemical characteristics, including insulin sensitivity, by CAPN10 variant.

The C allele at the UCSNP45 locus in CAPN10 is associated with idiopathic hirsutism, and UCSNP43 influences the hirsutism score.