Jeevanandam Saravanakumar, Muthu Prathibha K
Student, Saveetha Medical College and Hospital , Thandalam, Chennai, India .
Associate Professor, Department of Physiology, Saveetha Medical College and Hospital , Thandalam, Chennai, India .
J Clin Diagn Res. 2016 Dec;10(12):CM01-CM03. doi: 10.7860/JCDR/2016/21952.9000. Epub 2016 Dec 1.
Digit ratios, especially 2D:4D ratio, a potential proxy marker for prenatal androgen exposure shows sexual dimorphism. Existing literature and recent research show accumulating evidence on 2D:4D ratio showing correlations with various phenotypic traits in humans. Ratio of 2D:4D is found to correlate negatively to testosterone and positively to oestrogen in the foetus. Interestingly, it is constant since birth and not influenced by the adult hormone levels. Usually, males have lower ratios when compared to females. Prenatal androgen exposure and therefore, digit ratios have been reported to be associated with numerical competencies, spatial skills, handedness, cognitive abilities, academic performance, sperm counts, personalities and prevalence of obesity, migraine, eating disorders, depression, myopia, autism etc. The authors have attempted to write a brief account on the digit ratios and the dimorphism observed in various physiological, psychological and behavioural traits. Also, the authors have discussed the relevant molecular basics and the methods of measurement of digit ratios.
手指比例,尤其是2D:4D比例,作为产前雄激素暴露的潜在替代标志物呈现出性别二态性。现有文献和近期研究表明,越来越多的证据显示2D:4D比例与人类的各种表型特征相关。研究发现,胎儿的2D:4D比例与睾酮呈负相关,与雌激素呈正相关。有趣的是,该比例自出生起便保持恒定,不受成人激素水平的影响。通常情况下,男性的该比例低于女性。据报道,产前雄激素暴露以及手指比例与数字能力、空间技能、利手、认知能力、学业成绩、精子数量、性格以及肥胖、偏头痛、饮食失调、抑郁症、近视、自闭症等疾病的患病率有关。作者试图简要阐述手指比例以及在各种生理、心理和行为特征中观察到的二态性。此外,作者还讨论了相关的分子基础以及手指比例的测量方法。