ArticleFrontiers in endocrinology2013
No Evidence that 2D:4D is Related to the Number of CAG Repeats in the Androgen Receptor Gene.
Article in Frontiers in endocrinology, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers, 3 of them syntheses that pooled it.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
14 citing papers in PubMed, 3 syntheses or guidelines pooled it.
- Digit ratio (2D:4D) and transgender identity: new original data and a meta-analysis.Scientific reports · 2020Pooled it
- Digit ratio (2D:4D) in relation to substance and computer use: a meta-analysis.Journal of neural transmission (Vienna, Austria : 1996) · 2019Pooled it
- Genome-wide association study identifies nine novel loci for 2D:4D finger ratio, a putative retrospective biomarker of testosterone exposure in utero.Human molecular genetics · 2018Pooled it
- Effects of prenatal Leydig cell function on the ratio of the second to fourth digit lengths in school-aged children.PloS one · 2015Trial
- Androgen receptor gene polymorphism and biological age markers in men.Scientific reports · 2025Article
- Sex-moderated relationship between the 2D:4D ratio and circulating hormones in an adult Ghanaian population.Physiological reports · 2023Article
- Digit ratio (2D:4D) and maternal testosterone-to-estradiol ratio measured in early pregnancy.Scientific reports · 2022Article
- Associations between neurochemical receptor genes, 2D:4D, impulsivity and relationship quality.Biology letters · 2018Article
- Prognostic significance of the digit ratio after hormone therapy for prostate cancer: a prospective multicenter study.Scientific reports · 2017Article
- Digit ratio and autism spectrum disorders in the Avon Longitudinal Study of Parents and Children: a birth cohort study.BMJ open · 2015Article
- Social communication and emotion difficulties and second to fourth digit ratio in a large community-based sample.Molecular autism · 2015Article
- Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations.Frontiers in endocrinology · 2014Review
- Assessing prenatal and neonatal gonadal steroid exposure for studies of human development: methodological and theoretical challenges.Frontiers in endocrinology · 2014Article
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Abstract
The length ratio of the second to the fourth digit (2D:4D) is a putative marker of prenatal testosterone (T) effects. The number of CAG repeats (CAGn) in the AR gene is negatively correlated with T sensitivity in vitro. Results regarding the relationship between 2D:4D and CAGn are mixed but have featured prominently in arguments for and against the validity of 2D:4D. Here, I present random-effects meta-analyses on 14 relevant samples with altogether 1904 subjects. Results were homogeneous across studies. Even liberal estimates (upper limit of the 95% CI) were close to zero and therefore suggested no substantial relationship of CAGn with either right-hand 2D:4D, left-hand 2D:4D, or the difference between the two. However, closer analysis of the effects of CAGn on T dependent gene activation in vitro and of relationships between CAGn and T dependent phenotypic characteristics suggest that normal variability of CAGn has mostly no, very small, or inconsistent effects. Therefore, the lack of a clear association between CAGn and 2D:4D has no negative implications for the latter's validity as a marker of prenatal T effects.
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