Classic Congenital Adrenal Hyperplasia Due To 21-hydroxylase Deficiency – the Next Disease Included in The Neonatal Screening Program in Poland

Abstract Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by impaired cortisol synthesis. The most common form of CAH is caused by mutations in CYP21A, the gene encoding the adrenal steroid 21-hydroxylase enzyme. Deficiency of the enzyme leads to life-threatening adrenocortical insufficiency, which is not demonstrable during the first days of life. Additionally, some of the affected neonates have varying degrees of pathology of the external genitalia, classified as disorders of sex development (DSD). These make it difficult to recognize the sex of the affected neonate or lead to incorrect sex assignment. CAH has been included in neonatal screening programs in many countries of the world since the late of 1970s. The main benefit of the screening is early diagnosis and prevention of neonatal mortality in children with salt-wasting CAH. Early recognition of the disease is also helpful in correct sex assignment of DSD neonates. In 2016 Poland joined the group of countries which conduct neonatal screening for 21-hydroxylase deficient CAH and the condition is now included in the neonatal screening program. Therefore, it is possible to recognize the disease soon after birth in all Polish newborns and to start the prompt replacement steroid therapy. As the information on the suspicion or diagnosis of CAH in very young newborns has recently reached neonatologists, pediatricians, and general practitioners, and not only pediatric endocrinologists, the aim of this paper is to deliver the most necessary information on the disease to a wider group of doctors, not familiar with CAH.