ESPE Abstracts

Background: Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by a defect in cortisol biosynthesis. The most common form of CAH is the 21-hydroxylase deficiency (21-OHD), however, the incidence and the etiologic spectrum of other forms of CAH were not reported.

Objective and hypotheses: This study describes the etiological distribution and clinical characteristics of CAH in a single academic centre.

Method: This study included 190 patients with all forms of CAH. The diagnosis was confirmed by the clinical features, biochemical data, and molecular genetic analysis for the CYP21A2, StAR, CYP17A1, and POR genes.

Results: Of a total of 190 patients, 138 patients (72.6%) from 128 families were 21-OHD (104 salt-losing, 33 simple-virilizing, and 1 non-classic forms), 44 (15.2%) from 41 unrelated families had StAR defect, six (3.2%) had 17-hydroxylase/17,20-lyase deficiency, and two (1.1%) had P450 oxidoreductase (POR) deficiency. Ninety seven patients with salt-losing 21-OHD (97/104, 93.3%) were diagnosed in the neonatal period. Most girls of 21-OHD (75/76, 98.7%) presented with genital virilisation, whereas most boys (38/62, 61.3%) presented with salt-losing phenomenon within the first month of life. Four genetic female (46,XX) with simple virilizing form of 21-OHD were assigned as male because of delayed diagnosis. Most patients (42/44, 97.7%) with StAR defect presented with adrenal crisis in the neonatal period, while two late-onset patients showed skin hyperpigmentation after age two years. Six patients with CYP17A1 defect manifested with hypertension and primary amenorrhea during adolescent period. Two girls with POR deficiency displayed adrenal insufficiency, ambiguous genitalia, and craniosynostosis.

Conclusion: The most common cause of CAH was 21-OHD. Interestingly, lipoid CAH is the second common because of the founder mutation (p.Q258X) in Korea. Nationwide surveillance is needed to estimate the incidence and precise distribution of diverse aetiology of CAH, though newborn screening for 21-OHD is introduced.