Are 2D:4D finger-length ratios an indicator of androgenetic alopecia in males?

• Published in: Anais brasileiros de dermatología Vol. 91; no. 2; pp. 156 - 159
• Main Authors: Bilgic, Özlem, Altınyazar, Hilmi Cevdet, Eryılmaz, Dilek, Tuğrul, Zehra Ayça
• Format: Journal Article
• Language: English
• Published: Brazil Sociedade Brasileira de Dermatologia 01.04.2016
• Subjects: Adult; Aged; Alopecia; Alopecia - diagnosis; Alopecia - etiology; Androgens; Androgens - analysis; Androgens - physiology; Anthropometry - methods; Case-Control Studies; DERMATOLOGY; Female; Fingers; Fingers - anatomy & histology; Genetic Markers; Genetic Predisposition to Disease; Humans; Hyperandrogenism; Investigation; Male; Middle Aged; Organ Size; Predictive Value of Tests; Pregnancy; Prenatal Exposure Delayed Effects - diagnosis; Receptors, androgen; Reference Standards; Reference Values; Reproducibility of Results; Severity of Illness Index; Young Adult; Hyperandrogenism; Androgens; Alopecia; Fingers; Receptors, androgen
• ISSN: 0365-0596; 1806-4841; 1806-4841; 0365-0596
• DOI: 10.1590/abd1806-4841.20164622

Although the pathogenesis of androgenetic alopecia is not completely understood, the roles of genetic susceptibility and androgens are well-known. A lower ratio of the second digit (index finger = 2D) to the fourth digit (ring finger = 4D) length has been hypothesized to reflect prenatal androgen exposure and/or higher sensitivity to androgens. To determine the relationship between the second to fourth digit length ratio and androgenetic alopecia. Finger length measurements were made by a digital vernier calliper. Androgenetic alopecia severity was assessed using the Hamilton-Norwood scale. Subjects with an androgenetic alopecia score of grade III or more were included in the study. A total of 189 males with androgenetic alopecia and 171 healthy controls were enrolled in the study. The age range of participants was 19-65 years. The 2D:4D ratios in patients with androgenetic alopecia were significantly lower than those of healthy controls for the right hand; however, no significant difference was found for the left hand. Average 2D:4D ratios in androgenetic alopecia patients were also lower than in controls. No significant relationship was observed between androgenetic alopecia severity and 2D:4D ratios. Our data support the anatomical evidence of in utero androgen exposure and/or an individual's sensitivity to androgens in patients with androgenetic alopecia. Furthermore, the right hand 2D:4D ratio might be an indicator of androgenetic alopecia development.