MON-LB049 Central Precocious Puberty as a Presenting Sign of Non-Classical Congenital Adrenal Hyperplasia: Prevalence and Clinical Characteristics

Context: Central precocious puberty (CPP) may be the first presentation of non-classical congenital adrenal hyperplasia (NCCAH) in girls. Data on the prevalence and the clinical phenotype of CPP associated with NCCAH are sparse. Objectives: To study the clinical and laboratory characteristics that could differentiate idiopathic CPP from CPP associated with NCCAH and to determine the prevalence of NCCAH among girls with CPP. Design: Case-control study. Setting: Tertiary pediatric endocrinology institute. Participants and Methods: From 2008 to 2017, 147 girls who had undergone stimulation tests with gonadotropin-releasing hormone and Synacthen were diagnosed with CPP, of whom 7 (4.8%) were eventually diagnosed with NCCAH. These 7 patients together with 30 girls who presented with CPP in1984-2008 and were later diagnosed with NCCAH comprised the NCCAH group. Demographic, anthropometric, clinical, and laboratory data were compared between the NCCAH group and the 140 girls with idiopathic CPP (ICPP group). Results: No between-group differences were found in height, weight, body mass index, bone age, and Tanner stage. Mean basal levels of androstenedione, DHEAS, and 17-OHP were significantly higher in the NCCAH group, although ranges overlapped between the groups, and stimulated cortisol level was higher in the ICPP group. Conclusions: NCCAH was found in 4.8% of girls presenting with true CPP over a 10-year period, and no one parameter could differentiate between the diagnoses. Thus, in girls with true CPP from populations in which NCCAH is prevalent, assessment of adrenal androgens is required and ACTH test should be considered. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.