SHANK3 and type 2 diabetes mellitus: When investigating sub-phenotypes of T2DM, diabetic retinopathy has been identified to be associated with ACVRIC (rs4664229), ZFHX4 (rs61729527), WNT9B (rs4968281), SHANK3 (rs9616915), ZSCAN5A (rs7252603), and DCP1B (rs715146, rs1044950, rs113147414) gene.