Diagnosis and prevalence of Congenital Adrenal Hyperplasia (CAH) in Austrian children screened or not screened for CAH

Abstract

Prevalence of Congenital Adrenal Hyperplasia (CAH) is not exactly known in the Austria; a number of patients with CAH might not be diagnosed, especially males. CAH is in about 95 % of the cases due to a defect in the 21-hydroxylation (‘classical CAH’). Newborn screening for CAH, based on the measurement of 17α-hydroxyprogesterone (17-OHP) was shown to be efficient for diagnosis, and is part of the newborn screening programme in Austria since April 2001. In our study we compared 2 groups of children: Group A, children born in Styria (a province of Austria), 1992 – 2001, n = 119.001, m 61.256, and f 57.745; Group B, children born in Styria 2002 – 2011, n = 103.228, m 52.722, and f 50.506 In group A (patients not screened), CAH was diagnosed in 8 children (m 4; f 4); 4 of them with simple virilising (SV) 21-OH deficiency (m 3; f 1) and 4 with salt wasting (SV) 21-OH deficiency (m 1; f 3). In group B, 98,7 % of all newborns born in Styria could be screened by measuring 17-OHP in a dried blood spot on filter paper. Recall rate was 0,578 %. CAH was diagnosed in 10 children (m 3: f 7). 8 of them with SW (m 2; f 6), and 2 with 11β-hydroxylase deficiency (m 1; f 1). Whereas group A displayed the expected Mendelian sex ratio, group B showed a strong female predominance (m 3; f 7) Prevalence of CAH was 1:14.875 newborns in group A (not screened). In group B (newborns screened) prevalence was 1:10.132. If one exclude the 2 patients with 11s-hydroxylase deficiency from group B, prevalence of ‘classical CAH’ was 1:14.875 in group A, compared to 1:12.903 in group B. These data show that newborn screening for CAH seems to increase the rate of detection of CAH.