The review synthesizes findings from various studies that link PFAS exposure to alterations in DNA methylation in fetal tissues, such as changes in the methylation of genes like IGF2 and MEST, which are linked to disruptions in growth, neurodevelopment, immune function, and metabolic regulation, potentially increasing the risk of diseases such as diabetes and obesity. The gene discussed is MEST; the disease is obesity due to melanocortin 4 receptor deficiency.