IRS1 and polycystic ovary syndrome: We conclude that because the Taiwanese PCOS population does not include a sufficiently large number of cases of codon 972/513 mutation, these polymorphic alleles of IRS-1 are not a reliable or appropriate method of genetic diagnosis of PCOS featuring either AGT or insulin resistance, and that these polymorphic alleles of IRS-1 are quite rare amongst Taiwanese women.