Banyeh Moses, Nyewie Martha, Abdulai Abdul-Rafik, Nkansah Charles, Abbam Gabriel, Kangkpi Thea, Zogli Kervin Edinam, Shittu Shafiat Omotoyosi, Bure David, Wemegah Romarick Kofi, Azindow Mikail Ihsan, Yakubu Suleman, Seidu Musah, Baba Mohammed Madde, Essoun Elisha, Owireduwaa Nancy, Kolekang Augusta S
Department of Biomedical Laboratory Science, University for Development Studies, Tamale, Ghana.
Department of Public Health, Community Nurses Training School, Ministry of Health, Tamale, Ghana.
Physiol Rep. 2025 Jan;13(2):e70207. doi: 10.14814/phy2.70207.
The twin testosterone transfer (TTT) hypothesis posits that females with male co-twins (opposite-sex, OS) might develop male-typical traits due to higher prenatal testosterone exposure. This study explored whether females of OS have lower 2D:4D digit ratios and higher testosterone levels compared to females of same-sex (SS) twin pairs. Conducted in Tamale from January to December 2022, the study included 40 participants aged 18-27 years: 10 males of OS, 10 females of OS, and 20 females of SS twin pairs. Digit ratios (2D:4D) and serum testosterone levels were measured using computer-assisted analysis and ELISA, respectively. Results showed no significant differences in 2D:4D ratios between females of OS and SS twin pairs for either the right hand (0.960 ± 0.049 vs. 0.955 ± 0.042; p = 0.766) or the left hand (0.966 ± 0.048 vs. 0.968 ± 0.047; p = 0.908). Serum testosterone levels were lower in females of OS than females of SS twin pairs (0.4 ± 0.1 vs. 0.67 ± 0.34 nmol/L; p = 0.013), but this result was not significant after multiple testing corrections (p > 0.050). The findings indicate that the TTT hypothesis may not apply, or its effects on digit ratios and testosterone levels in females of OS twin pairs are weak and not statistically significant. Further studies involving larger samples are however, recommended.
双胞胎睾酮转移（TTT）假说认为，有男性双胞胎（异性，OS）的女性可能由于产前接触较高水平的睾酮而出现男性典型特征。本研究探讨了与同性（SS）双胞胎的女性相比，OS双胞胎的女性是否具有更低的2D:4D指长比和更高的睾酮水平。该研究于2022年1月至12月在塔马利进行，纳入了40名年龄在18 - 27岁的参与者：10名OS双胞胎男性、10名OS双胞胎女性和20名SS双胞胎女性。分别使用计算机辅助分析和酶联免疫吸附测定法（ELISA）测量指长比（2D:4D）和血清睾酮水平。结果显示，OS双胞胎女性和SS双胞胎女性右手（0.960±0.049对0.955±0.042；p = 0.766）或左手（0.966±0.048对0.968±0.047；p = 0.908）的2D:4D比值均无显著差异。OS双胞胎女性的血清睾酮水平低于SS双胞胎女性（0.4±0.1对0.67±0.34 nmol/L；p = 0.013），但在多次检验校正后该结果无统计学意义（p > 0.050）。研究结果表明，TTT假说可能不适用，或者其对OS双胞胎女性指长比和睾酮水平的影响较弱且无统计学意义。然而，建议开展涉及更大样本量的进一步研究。
