SRD5A1 and cardiac hypertrophy: Alternatively, for the prediction of cardiac therapeutic effects of 5α-reductase inhibitors, Mendelian randomization studies comparing individuals with or without genetic variations (e.g. SNPs) on the 5α-reductase encoding genes (Srd5a1-3) with regard to the development of cardiac hypertrophy and failure could be used to overcome biases related to observational studies52.