Newborn screening for congenital adrenal hyperplasia: beyond 17-hydroxyprogesterone concentrations

The Congenital Adrenal Hyperplasias (CAHs) comprise a group of autosomal recessive disorders due to defects in adrenal steroidogenesis.The most common is 21hydroxylase deficiency due to mutations in the 21hydroxylase (CYP21A2) gene.The clinical spectrum ranges from life-threatening adrenal insufficiency to minimal symptoms depending on the specific CYP21A2 mutations.1 The clinical phenotype generally reflects the functional activity of the mildest mutation.The prevalence of the classical forms, salt-losing and simple virilizing, differs among populations ranging from approximately 1 in 6000 in India to 1 in 19,000 in Japan. 2 The prevalence of non-classic or mild CAH is higher and was reported to be 1 in 2000 among Caucasians in the United States.3 One goal of pediatrics is prevention of disease as exemplified by vaccine development.Another area for prevention is the development of programs to screen and detect newborn infants for whom early intervention is beneficial.For the pediatric endocrinologist, Newborn Screening (NBS) programs for congenital hypothyroidism provide a model in