The importance and implications of preconception genetic testing for accurate fetal risk estimation in 21-hydroxylase congenital adrenal hyperplasia (CAH).

Preconception genetic testing should be offered to all patients with 21-hydroxylase congenital adrenal hyperplasia. We report how the preconception genetic testing of a lady and her partner dramatically changed the estimated risk to their offspring and the major implications the results had on pregnancy planning. The risk of conceiving a female fetus with congenital adrenal hyperplasia brings in considerations of prenatal dexamethasone therapy and prenatal diagnosis. We also highlight the differences between genetic testing on a research and clinical basis.