The Genetics of Autism and Steroid-Related Traits in Prenatal and Postnatal Life

The document investigates the genetic factors of autism and their interaction with steroid-related traits. Autism is largely heritable, with 64-93% heritability estimates from twin studies, but identified genes account for less than 10% of the variance. A study involving 18,381 autistic individuals discovered five significant genetic loci. The research found no overlap between autosomal genes expressed in male and female placentas and high-confidence autism genes, but a significant overlap was found on the X-chromosome. The study also found significant genetic correlations between autism and age of menarche and alopecia. Higher genetic likelihood for autism was associated with an earlier age of menarche and reduced likelihood for hair loss. The study found no genetic correlation between autism and the genetic variance associated with testosterone, estradiol, or PlGF levels, or with genotypes associated with polycystic ovaries syndrome (PCOS). However, a negative genetic correlation was found between autism and genotypes associated with hair loss in men (androgenic alopecia), suggesting that autism may be associated with higher levels of estrogens. The study concludes that while the genetics of autism did not correlate with steroid hormone levels, they did correlate negatively with age of menarche and androgenic alopecia, suggesting a complex interaction between steroid hormones, the HPG axis, and cellular maturation processes. Further research is needed to understand these correlations.