7131 The Morbidity Pattern in Females with 45,X/46,XY Mosaicism

Abstract Disclosure: K. Stochholm: None. C.H. Gravholt: None. A. Berglund: None. Background: Turner syndrome (TS) includes females with 45,X/46,XY mosaicism, a rare variant with a prevalence of 2.1 per 100,000 newborn females. Specific knowledge about their associated health outcomes is limited. Aim: To investigate the morbidity pattern in a national cohort of females with 45,X/46,XY. Methods: Data were retrieved for all females diagnosed with 45,X/46,XY from 1960 to 2018 (n=46) and for 4,377 age-matched females from the general population. Morbidity were investigated using Cox regression analysis on registry data regarding hospital diagnoses, redeemed medication, and surgery codes. Results: 45,X/46,XY was associated an increased overall risk of a hospital diagnosis (Hazard ratio (HR): 1.6, confidence interval (CI): 1.2-2.1). The risk of undergoing surgery was significantly increased before the age of 40 years (HR: 1.6, CI: 1.0-2.5), but not in total (HR: 1.2, CI: 0.8-1.7). The HR of redeeming medication was similar to comparators, HR: 1.2, CI: 0.86-1.66. Dividing hospital diagnoses into 18 chapters according to the International Classification of Diseases, 45,X/46,XY had a significantly increased risk of diagnoses due to endocrine disorders (HR=3.6, CI: 2.3-5.8), disorders of the ear (HR=7.1, CI: 4.5-11.3), disorders of the circulation (HR=2.8, CI: 1.7-4.9), and due to congenital malformations (HR=25.1, CI: 17.5-35.8). Among specific diagnoses with a significantly increased risk were gonadal dysfunction, valve diseases, hypertensive diseases, diseases of arteries and aneurisms. Surgery due to disorders of the heart and greater vessels were significantly increased in total (HR=9.3 CI: 2.2-40.4), as were surgery on the aortic valve (HR=36.9, CI: 3.3-409.2), and on female genitalia (HR=2.1, CI: 1.3-3.4), whereas obstetric surgery was significantly decreased (HR 0.2, CI: 0.0-0.7). In females with 45,X/45,XY, there were no registrations related to gonadoblastoma as neither ovarian surgery nor registrations on cancer of the ovary were present. The HR of redeeming a prescription was significantly decreased in the categories of dermatologicals (HR=0.6, CI: 0.4-0.9), musculoskeletal (HR=0.6, CI: 0.4-0.9), antiparasitics (HR=0.5, CI: 0.2-0.8), and in respiratory system (HR=0.6 CI: 0.4-0.9), and significantly increased in systemic hormones (HR=2.2, CI: 1.4-3.7) and in sex hormones (HR=2.9, CI: 2.0-4.1). Conclusion: 45,X/46,XY in females is associated with an increased morbidity with a skewed pattern, as indicated by an overall increased risk of hospital diagnoses, but a unaffected usage of prescribed medication. Surgical procedures were affected with a pattern as in others with Turner syndrome, with a surprisingly absent registration of procedures linked to gonadoblastoma. This study is most likely curtailed by the limited number of females diagnosed with 45,X/46,XY, however the imperative for systematic follow-up is underlined. Presentation: 6/1/2024