Aim: Increased clinical attention toward less severe cases of congenital adrenal hyperplasia (CAH) may affect both incidence and prevalence. In this nationwide population-based cohort study, we estimate incidence, prevalence, and age at diagnosis of CAH according to subtype and sex.
Patients and Methods: Individuals registered with a diagnosis of CAH during 1977 to 2018 were identified in the Danish National Patient Registry, by genetic data and via the National neonatal screening program (n=3368). If registered at an endocrine, pediatric or gynecological department, medical records were reviewed to validate the CAH diagnosis (n=1876).
Results: Combined, 462 individuals (females: n=290) had CAH with the following distribution of subtypes: salt-wasting (SW): n=222 (103 males), simple virilizing (SV): n=59 (21 males), non-classic (NC): n=142 (34 males), other subtypes: n=24, and unknown subtype: n=15. The average incidence of CAH was 1.9 per 1,000,000 females and 1.2 per 1,000,000 males. Among newborns, the maximum average prevalence of females and males diagnosed with CAH was observed during 1967-2011 and 1967-2016, respectively, being 15 per 100,000 females and 9 per 100,000 males. During the same period, and stratified according to subtype, SW CAH occurred with a prevalence of 6.3 and 5.5 per 100,000 newborn females and males, respectively. SV CAH occurred with a prevalence of 2.0 and 1.1 per 100,000 newborn females and males respectively and NC CAH occurred with a prevalence of 5.6 and 1.8 per 100,000 newborn females and males, respectively. Females and males with SW-CAH were diagnosed at a median age of 6 days, IQR [1-10] and 10 days, IQR [8-20], respectively and with a significant decrease of three days among males (P<0.0001), after introduction of the neonatal CAH screening program. The median age at diagnosis of SV CAH was 5.4 years, IQR[2.5-9] and 5.14 years, IQR[4.4-6.9] in females and males, respectively (P=0.73) and for NC CAH 15.6 years, IQR[8.0-22.6] and 9.5 years, IQR[7.2-23.2] in females and males, respectively (P=0.26).
Conclusion: We identified the entire Danish cohort of individuals with CAH and estimated a total maximum average prevalence of 15 CAH females per 100,000 newborn females, which is higher than in previous studies, and 9 CAH males per 100,000 newborn males. Males with SV-CAH and NC-CAH suffer significantly from non-diagnosis compared to females. Individuals with NC-CAH are diagnosed late.
15 Sep 2022 - 17 Sep 2022