Zhao et al. investigated the methylation patterns of TGFB1, BAX, IGFBP3, PRKCB, PSEN2, and CCL2 in the peripheral blood of 42 ASD patients and 26 TD patients, finding that the rate of the methylation of TGFB1 was decreased in ASD and was positively associated with the interaction ability score [50]. The gene discussed is PSEN2; the disease is thanatophoric dysplasia.