Yildiz M, Isik E, Abali ZY, et al. - As 11β-hydroxylase deficiency (11βOHD) occurs rarely, data concerning the differences in clinical and biochemical characteristics of classic (C-11βOHD) and non-classic 11βOHD (NC-11βOHD) are lacking. Researchers sought to describe a multicenter pediatric cohort with 11βOHD. They retrospectively retrieved the clinical and biochemical characteristics of 102 patients (C-11βOHD; n=92, NC-11βOHD; n=10) from 76 families (46,XX; n=53) who had biallelic CYP11B1 mutations (novel 9 out of 30). Five 46,XX patients (10%) were raised as males. Initially, misdiagnoses with 21-hydroxylase deficiency were made for 19 patients (19%). Adult height in female and male patients was 152 cm (-1.85SDS) and 160.4 cm (-2.56SDS), respectively. Ambiguous genitalia were not observed in any of the NC-11βOHD girls (C-11βOHD 100%) and none of the NC-11βOHD patients were hypertensive (C-11βOHD 50%). Relative to NC-11βOHD, C-11βOHD patients were diagnosed earlier, had higher bone age-to-chronological age and lower adult height. All patients had low concentrations of 11-oxygenated androgens and 21-deoxycortisol. NC-11βOHD had normal baseline ACTH and stimulated cortisol. C-11βOHD vs NC-11βOHD patients had higher baseline cortisol, cortisone, 11‐deoxycortisol, 11-deoxycorticosterone and corticosterone concentrations, and 11‐deoxycortisol/cortisol, 11-deoxycorticosterone/cortisol and androstenedione/cortisol ratios. To segregate C-11βOHD, NC-11βOHD and control groups, 100% specificity was recorded with the 11‐deoxycortisol/cortisol ratio > 2.2, < 1.5 and < 0.1 , respectively. Overall observations suggest that due to relatively mild clinical presentation, NC-11βOHD can escape from clinical attention. However, the diagnosis, differential diagnosis, and subtyping of 11βOHD are possible via assessing steroid profiles.