To Örebro University

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: To study the prevalence of autoimmune diseases in TS.

DESIGN AND SETTING: A cross sectional, longitudinal, 25-year follow-up study of patients from adult Turner Centers at the University Hospitals, Sweden. PARTICIPANTS, INTERVENTIONS: During 1994-2020, 503 women aged 16-71 years, with TS were evaluated consecutively every 5th year according to national guidelines. A random population sample of women, n = 401, 25-44 years, from the WHO MONICA project served as controls.

MAIN OUTCOME MEASURES: Serum TSH, free T4, vitamin B12, anti-thyroperoxidase (anti-TPO) and anti-transglutaminase 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 B12 deficiency 5% to 12%, celiac disease 4% to 7%, positive anti-TPO 26% to 41% and anti-transglutaminase antibodies 6% to 8% (p < 0.0001 vs controls). Type 1 diabetes and Addison´s disease was rare. The only interrelationship was between hypothyroidism and vitamin B12-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.

CONCLUSIONS: In women with TS up to over 80 years of age, more than half developed hypothyroidism, mainly autoimmune, during follow-up. Awareness of vitamin B12 deficiency and celiac disease throughout life is also recommended in women with TS.