Landscape of congenital adrenal hyperplasia cases in adult endocrinology clinics of Türkiye-a nation-wide multicentre study

Background and aims: Congenital adrenal hyperplasia (CAH) is a group of disorders that affect the production of steroids in the adrenal gland and are inherited in an autosomal recessive pattern. The clinical and biochemical manifestations of the disorder are diverse, ranging from varying degrees of anomalies of the external genitalia to life-threatening adrenal insufficiency. This multicenter study aimed to determine the demographics, biochemical, clinical, and genetic characteristics besides the current status of adult patients with CAH nationwide.

Methods: The medical records of 223 patients with all forms of CAH were evaluated in the study, which included 19 adult endocrinology clinics. A form inquiring about demographical, etiological, and genetic (where available) data of all forms of CAH patients was filled out and returned by the centers.

Results: Among 223 cases 181 (81.16%) patients had 21-hydroxylase deficiency (21OHD), 27 (12.10%) had 11-beta-hydroxylase deficiency (110HD), 13 (5.82%) had 17-hydroxylase deficiency (17OHD) and 2 (0.89%) had 3-beta-hydroxysteroid-dehydrogenase deficiency. 21OHD was the most prevalent CAH form in our national series. There were 102 (56.4%) classical and 79 (43.6%) non-classical 210HD cases in our cohort. The age of the patients was 24.9 ± 6.1 (minimum-maximum: 17-44) for classical CAH patients and 30.2 ± 11.2 (minimum-maximum: 17-67). More patients in the nonclassical CAH group were married and had children. Reconstructive genital surgery was performed in 54 (78.3%) of classical CAH females and 42 (77.8%) of them had no children. Thirty-two (50.8%) NCAH cases had homogenous and 31 (49.2%) had heterogeneous CYP21A2 gene mutations. V281L pathological variation was the most prevalent mutation, it was detected in 35 (55.6%) of 21OHD NCAH patients.

Conclusion: Our findings are compatible with the current literature except for the higher frequency of 110HD and 17OHD, which may be attributed to unidentified genetic causes. A new classification for CAH cases rather than classical and non-classical may be helpful as the disease exhibits a large clinical and biochemical continuum. Affected cases should be informed of the possible complications they may face. The study concludes that a better understanding of the clinical characteristics of patients with CAH can improve the management of the disorder in daily practice.