Congenital central hypothyroidism Congenital central hypothyroidism (C-CH, also known as secondary hypothyroidism) C-CH is a rare condition characterised by abnormally low levels of thyroid-stimulating hormone (TSH) released by the pituitary gland at the base of the brain. The low TSH level leads to low thyroid hormone (T4) levels because the thyroid gland is not stimulated in the normal way. Secondary hypothyroidism can go undiagnosed in the UK because the condition is not picked up as part of the current blood spot screening programme. This is because the current programme only identifies babies with primary hypothyroidism where TSH levels are abnormally high because of an abnormal thyroid gland. Some babies with C-CH have problems with the way the pituitary makes other hormones besides TSH and can be detected earlier as a result. However, some affected babies (perhaps around a half of babies with C-CH) just have a problem with TSH release. Without treatment, C-CH can affect a young person’s ability to grow, learn and develop normally. We are currently working with researchers who would like to explore how we might achieve earlier diagnosis of C-CH and the likely associated benefits to children, families and society as a whole. If you, or your child, has been diagnosed with C-CH and you would like to share your experiences with the researchers who are doing this work we would love to hear from you. Please email [email protected] with the subject heading ‘Central CH’.