A study comparing HM cases with typical cases (4 to 12 years old) revealed that myopia-related genes such as suppressor of cytokine signaling 1 (SOCS1), zinc and ring finger 3 (ZNRF3), presenilin 1 (PSEN1), PAX6, adaptor related protein complex 1 subunit beta 1 (AP1B1), adenylate cyclase 3 (ADCY3), the regulator of G protein signaling 5 (RGS5), serum response factor (SRF) and growth factor receptor binding protein 2 (GRB2), are highly methylated, promoting the development of myopia 29. This evidence concerns the gene PSEN1 and myopia.