Neonatal Screening for Congenital Adrenal Hyperplasia in the Czech Republic - Results of a One-year Pilot Study in Males
Abstract
Congenital adrenal hyperplasia (CAH) is a potentially fatal inborn endocrine disease due to defective steroid synthesis, the most prevalent being deficiency of the enzyme P450c21 (21-hydroxylase). Neonatal screening of CAH is based on measurement of 17-α-hydroxyprogesterone (17-OHP) in a dried blood spot.
It makes possible recognition of the disease, prevention of metabolic crisis (salt-wasting SW) in patients and early introduction of therapy with the virilizing (SV) form. The first year of the pilot study of neonatal screening of CAH in the Czech Republic was made in the laboratory of neonatal screening of the University Hospital Prague - Kralovske Vinohrady from January 1st up to December 31st, 2001, only in males.
We analysed 26 502 dried blood spots (incl. 1431 from boys with birth weights less than 2500 g). The 17-OHP concentration was measured using DELFIA (Neonatal 17-OH-progesterone kit, Wallac Oy, Turku, Finland).
Additionally, the age at blood sampling and the period up to the delivery to the laboratory were evaluated in 2718 newborns. A 17-OHP concentration over 30 nmol/l was recorded in 55 of 25 071 males with a birth weight of 2500 g or more which led to a recall (recall rate 0.219 %).
In males with a birth weight less than 2500 g, the recall rate was 3.843% (55 of 1431) using weight adjusted cut off limits. A clearly positive 17-OHP concentration over 90 nmol/l (range, 108-760) was found in 7 boys (all birth weight over 2500 g).
All were urgently admitted to hospital as urgent cases CAH was confirmed in 3 of them (once, SV; twice, SW; positive predictive value 0.43). The overage day of blood sampling was 5 (range 2-11) and period up to delivery to the laboratory 5 days (range 0-29) in newborns with birth weights over 2500 g, day 6 (2-32) and 5 days (0-33) in subjects with birth weight 1500-2499 g and day 8 (range 2-56) and 5 days (range 1-23) in subjects with birth weight less than 1500 g.
The results of one year of the pilot study proved the feasibility and efficiency of the neonatal screening of CAH in the Czech Republic.