5-alpha Reductase Deficiency in Two Siblings: A Case Report

Abstract

A deficiency of 5-alpha reductase is a rare genetic disorder that affects 46,XY patients. The lack of enzyme causes inadequate differentiation of the gonads, leading to ambiguous genitalia or complete feminization of the external genitalia. Two sisters presented to their endocrinologist complaining of primary amenorrhea. Molecular studies revealed the SRD5A2 His231Arg gene mutation and karyotype showed 46,XY genotype. The diagnosis was supported by their high testosterone/dihydrotestosterone (DHT) ratio, response to the hCG stimulation test and their elevated sex hormone binding globulin (SHBG) levels. The siblings continued to identify as the female gender and were placed on oral premarin to develop secondary female sexual characteristics. In conclusion, any individual presenting with ambiguous genitalia, primary amenorrhea or virilization should be investigated for 5-alpha reductase deficiency by conducting a karyotype and full hormone profile.




J Med Cases. 2016;7(7):263-265
doi: http://dx.doi.org/10.14740/jmc2482w