Autoimmune Disease in Turner Syndrome in Sweden: An up to 25 Years' Controlled Follow-up Study

Context: Turner syndrome (TS) is the most common chromosomal aberration in women; it is the result of structural or numeric abnormalities in the X chromosome. Autoimmune hypothyroidism has been recognized as one of the more prominent disorders associated with TS.Objective: This work aimed to study the prevalence of autoimmune diseases in TS.Methods: A cross-sectional, longitudinal, 25-year follow-up study was conducted of patients from adult Turner centers at the University Hospitals, Sweden. During 1994 to 2020, a total of 503 women aged 16 to 71 years with TS were evaluated consecutively every fifth year according to national guidelines. A random population sample of women, n = 401, aged 25 to 44 years, from the World Health Organization Monitoring of Trends and Determinants for Cardiovascular Disease (MONICA) project served as controls. Serum thyrotropin, free thyroxine, vitamin B-12, antithyroid peroxidase (anti-TPO), and antitransglutaminase antibodies were measured.Results: Mean follow-up time (years) was 16 +/- 7 for patients and 13 +/- 1 for controls. From study start, the prevalence increased in TS for hypothyroidism 40% to 58%, vitamin B-12 deficiency 5% to 12%, celiac disease 4% to 7%, positive anti-TPO 26% to 41%, and antitransglutaminase antibodies 6% to 8% (P < .0001 vs controls). Type 1 diabetes and Addison disease were rare. The only interrelationship was between hypothyroidism and vitamin B-12 deficiency, both in TS and controls. No association between autoimmune disease and karyotype, antecedent growth hormone treatment, or ongoing estrogen hormone replacement, was seen in TS.Conclusion: In women with TS up to older than 80 years, more than half developed hypothyroidism, mainly autoimmune, during follow-up. Awareness of vitamin B-12 deficiency and celiac disease throughout life is also recommended in women with TS.