Among the four SNPs shared by HbA1c and PCOS (rs8047587, rs1265564, rs2238689 and rs4731113), the most significant (rs1265564, pCPASSOC=2.91×10–13) was near CUX2, a gene that is expressed in neural tissues and that has previously been reported to be associated with insulin-dependent diabetes. Here, CUX2 is linked to type 1 diabetes mellitus.