 Other populations at increased risk for coeliac disease, with prevalence rates ranging from 5% to 10%, include individuals with Down and Turner syndromes, type 1 diabetes, and autoimmune thyroid disease, including both hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid).Historically, coeliac disease was thought to be rare, with a prevalence of about 0.02%.The reason for the recent increases in the number of reported cases is unclear.