Santiwatana S, et al. - This study was undertaken to determine if there is any link between early-onset skewed X chromosome inactivation (XCI), defined as having 80% or greater of the cells preferentially inactivated on the same X chromosome, and childhood autoimmune thyroid disease (ATD) by analyzing data of 91 female ATD patients, aged 3-20 years and 57 age-matched, female controls. A higher occurrence of skewed XCI was seen in patients with Hashimoto thyroiditis vs those with Graves disease. Researchers found that occurrence of skewed XCI was increased in childhood ATD, suggesting a link between development of pediatric ATD and skewed XCI.