In Study 2, autism-related common genetic variance (captured via GWAS) is studied in association with the genetic variants relating to steroid hormone levels in middle-aged or older adults (UK Biobank) and of the placental growth factor (PlGF), as well as to the genetics of complex steroid-related traits (publicly available data on age of menarche, PCOS and androgenic alopecia). This evidence concerns the gene PGF and autism.