ESPE Abstracts

Background: Congenital adrenal hyperplasia (CAH) is one of the most common inherited endocrinal disorders. Steroid 11β hydroxylase deficiency (11βOHD) is the 2nd most common form of CAH. It is a rare AR disorder caused by CYP11B1 mutations with an incidence of 100 000–200 000 in overall population.

Objective and hypotheses: To detect 11β hydroxylase deficiency in patients presenting with clinical manifestations and hormonal findings suggestive of CAH.

Method: The study was cross sectional, including 22 patients (16 females and six males) with CAH, divided into two groups (11β hydroxylase deficiency and 21 hydroxylase deficiency) according to 11 deoxycortisol/cortisol ratio. Both groups were studied regarding history (demographic data, family history, age at presentation, different presentations), examination (BP measurement, auxology, genitalia, pubertal staging) and investigations including laboratory tests (adrenal precursors, PRA, Na, K) and imaging (pelvic U/S).

Results: Both studied groups showed no statistically significant difference regarding age at presentation, sex, consanguinity, different clinical presentations, BP assessment, auxology, Prader scoring in females with atypical genitalia, adrenal precursors (except for 11 deoxycortisol level and 11 deoxycortisol/cortisol ratio which were highly significant with a P value of <0.001), PRA, Na and K levels. Two 11βOHD cases had molecular studies done, their sequence analysis revealed a single base substitution in exon 8, codon 448 from arginine (CGC) to histidine (CAC).

Conclusion: Differentiation is very difficult between 21OHD and 11βOHD and in order to properly diagnose 11βOHD, measurement of 11 deoxycortisol is mandatory for all cases with suspected CAH, especially that routine use of mineralocorticoids in 21OHD might be injurious in 11βOHD prone to hypertension. Furthermore, the need for genetic studies is increasing especially for those patients with atypical presentation (salt wasting 11βOHD).