Open Access2D:4D Ratio and its Implications in Medicine
Author(s) -
Saravanakumar Jeevanandam,
Prathibha K Muthu
Publication year - 2016
Publication title -
journal of clinical and diagnostic research
Language(s) - English
Resource type - Journals
eISSN - 2249-782X
pISSN - 0973-709X
DOI - 10.7860/jcdr/2016/21952.9000
Subject(s) - digit ratio , sexual dimorphism , androgen , migraine , testosterone (patch) , psychology , cognition , phenotype , clinical psychology , developmental psychology , medicine , hormone , endocrinology , biology , neuroscience , genetics , gene
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.