Congenital adrenal hyperplasia (CAH) is a prevalent cause of newborn genital ambiguity and adrenal insufficiency. The most common form of CAH, steroid 21-hydroxylase deficiency, accounts for about 95% of affected individuals. The main forms of this disease are classic salt-wasting, simple virilizing, and nonclassic. Phenotypic variability is attributable to allelic variation in the gene encoding active steroid 21-hydroxylase, CYP21A2. The disease is inherited as an autosomal recessive trait. There are more than 80 known disease-causing mutations, but about 10 mutations comprise 80% to 90% of alleles in most populations. It has become clear that there is a spectrum of disease, ranging from severe to mild, depending on which CYP21A2 mutations a patient carries. Genotyping can be useful in verifying the diagnosis of CAH in newborn screening programs primarily based on hormone assays and is also valuable in prenatal diagnosis.
Chief, Division of Pediatric Endocrinology, Schneider Children’s Hospital, New Hyde Park, New York; and Professor of Pediatrics, NYU School of Medicine, New York, New York.
Dr. Speiser has disclosed that she is the recipient of research/grant funding from Pfizer Inc. and is a member of the speakers bureaus of Eli Lilly & Company and Pfizer Inc.
Reprints: Phyllis W. Speiser, MD, Schneider Children’s Hospital, 269-01 76th Avenue, New Hyde Park, NY 11040. E-mail: firstname.lastname@example.org.
Chief Editor’s Note: This article is the 3rd of 36 that will be published in 2005 for which a total of up to 36 Category 1 CME credits can be earned. Instructions for how credits can be earned precede the CME Examination at the back of this issue.