18790
Anogenital Distance (AGD): A Novel Biomarker of Elevated Fetal Androgen Activity in Toddlers with Autism?
Thursday, May 14, 2015: 5:30 PM-7:00 PM
Imperial Ballroom (Grand America Hotel)
A. L. Pohl1, L. Ruta2,3, A. Gagliano4, M. L. Eisenberg5, M. Hsieh6 and S. Baron-Cohen1,7, (1)Autism Research Centre, University of Cambridge, Cambridge, United Kingdom, (2)Stella Maris Scientific Institute, Calambrone (Pisa), Italy, (3)Institute of Clinical Physiology, National Research Council of Italy, Messina, Italy, (4)Department of Paediatrics, University of Messina, Messina, Italy, (5)Department of Urology, Stanford University, Stanford, CA, (6)Department of Urology, Children's National Health System, Washington, DC, (7)CLASS Clinic, Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom
Background: During a critical period of prenatal brain development, fetal steroid hormones, particularly fetal testosterone (fT), may contribute to the etiology of autism, as fT is elevated in children who go on to develop autism spectrum conditions (ASC) and is positively correlated to autistic traits in typically developing (TD) children. Direct measure of fetal steroids is only possible in convenience samples of women undergoing amniocentesis. Thus, a robust biomarker of fT exposure is needed to assess the contribution of fT to the autism phenotype in wider studies. Right hand 2
nd digit to 4
thdigit (R2D:4D) ratio, a biomarker of fT activity, has been previously shown to be masculinized in ASC. However, R2D:4D is also influenced by postnatal steroid levels, and the effect size of sex upon fT is weak, especially in early development, limiting its utility as a biomarker of fT activity. Anogenital distance (AGD), which is determined by fT in the prenatal male programming window (gestational weeks 8-14), has been suggested as a superior biomarker of fT activity.
Objectives: To test whether toddlers with ASC have increased AGD, indicative of increased fetal androgen activity, compared to controls.
Methods: Anopenile distance was measured in male toddlers with ASC (n=29) and in male controls (n=24) using electronic callipers. Groups were frequency matched on age and BMI (ASC n=28, control n=12).
Results: Groups did not differ on age or BMI (p>0.05). Males with ASC had a longer AGD than controls. (Mean ± SD; ASC 80.6 ± 7.4, CTR 74.8 ± 8.9, p = 0.017, Cohen’s d=0.71).
Conclusions: Consistent with the predicted role of fT in the development of autism, children with ASC had significantly greater AGD, indicating increased fT activity during gestational weeks 8-14. With further research, AGD may be a useful biomarker, measurable at birth, for risk of ASC linked to elevated prenatal testosterone activity in autism.
