Androgen Receptor (AR) Gene (CAG)n and (GGN)n Length Polymorphisms and Symptoms in Young Males With Long-Lasting Adverse Effects After Finasteride Use Against Androgenic Alopecia

INTRODUCTION Long-term adverse symptoms of men who used oral finasteride against androgenic alopecia have been recently described as post-finasteride syndrome (PFS). AIM To determine whether (CAG)n-rs4045402 and (GGN)n-rs3138869 polymorphisms in the androgen receptor (AR) gene are implicated in PFS. METHODS AR polymorphisms were studied according to PFS symptoms in 66 white participants (31.8% Italian, 28.8% American, and 39.4% other). MAIN OUTCOME MEASURES Symptoms were investigated by an ad hoc 100-item questionnaire and the Arizona Sexual Experience Scale and Aging Male Symptom Scale (AMS). (CAG)n and (GGN)n repeats were categorized as short ([CAG]9-19, [GGN]<23), medium ([CAG]20-24, [GGN]23), or long ([CAG]25-37, [GGN]>23). RESULTS Median age was 32 years, duration of finasteride use was 360 days, and time from finasteride discontinuation was 1,053 days. We observed several frequency differences in symptoms according to (CAG)n and (GGN)n repeat numbers. Three AMS items were worse for medium (GGN)23 than for long (GGN)>23 carriers and one item was worse for short (GGN)<23 carriers. The AMS item for decrease in sexual desire or libido was worse for short (CAG)9-19 carriers than for medium (CAG)20-24 carriers. Through the ad hoc questionnaire, significant findings in (CAG)n and/or (GGN)n repeats were obtained for penile discomfort, loss of scrotal sensitivity, scrotal discomfort, less pubic hair, loss of perceived perineal fullness, increased sperm density, involuntary muscle spasms, loss of muscle tone, increased weight (>2 kg), increased skin dryness, and onset of symptoms after finasteride use. CONCLUSION This study showed that short and/or long (CAG)n and (GGN)n repeats had different frequencies according to symptoms reported by patients with PFS, likely reflecting the vast array of genes modulated by the AR. This study showed a U-curvilinear profile of (CAG)n repeats for skin dryness symptoms, where the two extremes exhibited a worse condition than medium repeats. Further studies are necessary to investigate the PFS pathophysiology using a precision medicine approach.