Second to Fourth Digit Ratio (2D:4D) in Female Patients With Systemic Sclerosis: Evidence for Prenatal Androgen Exposure
American Journal of Human Biology, cilt.38, sa.2, 2026 (SCI-Expanded, SSCI, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 38 Sayı: 2
- Basım Tarihi: 2026
- Doi Numarası: 10.1002/ajhb.70224
- Dergi Adı: American Journal of Human Biology
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Social Sciences Citation Index (SSCI), Scopus, Anthropological Literature, BIOSIS, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO), Natural Science Collection (ProQuest), Biological Science Database (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
- Anahtar Kelimeler: 2D:4D, autoimmune disease, prenatal androgen, systemic sclerosis, testosterone
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Kütahya Sağlık Bilimleri Üniversitesi Adresli: Evet
Özet
Objectives: Systemic sclerosis (SSc) demonstrates marked female predominance, suggesting hormonal influences in disease pathogenesis. The second-to-fourth digit ratio (2D:4D), a biomarker of prenatal androgen exposure, has been associated with various autoimmune conditions. This study investigated whether 2D:4D ratios differ between female SSc patients and healthy controls. Methods: This case–control study enrolled 33 women with SSc (2013 ACR/EULAR criteria) and 30 age-matched healthy female controls. Second and fourth digit lengths were measured bilaterally using digital calipers, and 2D:4D ratios were calculated. Between-group differences were analyzed using Welch's t-test and Mann–Whitney U test. Results: SSc patients demonstrated significantly lower 2D:4D ratios than controls bilaterally (right hand: 0.950 ± 0.029 vs. 1.022 ± 0.012, p < 0.001; left hand: 0.951 ± 0.030 vs. 1.022 ± 0.012, p < 0.001). Effect sizes were substantial (Cohen's d > 2.8). The lower ratios resulted from longer fourth digits rather than shorter second digits, consistent with elevated prenatal androgen exposure. Conclusions: Female SSc patients exhibit significantly lower 2D:4D ratios than healthy controls, suggesting higher prenatal testosterone exposure. These findings support the hypothesis that the prenatal hormonal environment may contribute to autoimmune disease susceptibility.