Idiopathic hirsutism: local and peripheral expression of aromatase (CYP19A) and 5α-reductase genes (SRD5A1 and SRD5A2).

OBJECTIVE To evaluate idiopathic hirsutism etiology via molecular studies testing peripheral and local aromatase and 5α-reductase expression. DESIGN Assessment of the expression of messenger RNA (mRNA) for type 1 and 2,5α-reductase isoenzyme gene (SDR5A1, SDR5A2) and aromatase (CYP19A) in dermal papillae cells and peripheral blood mononuclear cells. SETTING University hospital. PATIENT(S) 28 untreated idiopathic hirsute patients and 20 healthy women (controls). INTERVENTION(S) Human skin biopsies and peripheral venous blood. MAIN OUTCOME MEASURE(S) SDR5A1, SDR5A2, CYP19A gene expression in skin biopsies and peripheral blood. RESULT(S) A statistically significant reduction of SRD5A1, SRD5A2, and CYP19A gene expression was found in the dermal papillae cells and peripheral blood mononuclear cell between the study and control group. CONCLUSION(S) Further study, including protein expression and enzyme activity assays, are warranted to characterize the paradoxically low gene expression levels of local 5α-reductase and aromatase in women with idiopathic hirsutism.