Reversing the Impact of a Missing Hormone
Building on the discoveries that allowed mass screening for Phenylketonuria (PKU), NICHD-supported researchers developed a similar screening method for congenital hypothyroidism (CH). CH is a metabolic condition that results from problems with the thyroid gland. The thyroid gland makes thyroid hormone (also called thyroxine), which the body uses to regulate many of its functions, including temperature and energy levels.
In most cases of CH, problems with the thyroid start in the womb. Because the gland is missing, incomplete, or in the wrong place, the body does not produce enough thyroid hormone. Missing or low levels of the hormone lead to abnormal growth and development, as well as slower intellectual functioning. Simply providing thyroid hormone at normal levels can prevent the effects and health problems of CH.
During pregnancy, the mother's thyroid gland makes up for the problems with the fetus' thyroid gland by making enough thyroid hormone for normal development. But, after birth, low levels of thyroid hormone cause slow growth, especially in the brain. If undetected and untreated, CH causes intellectual disability that can not be reversed.
The successes surrounding PKU research offered hope that CH could also be detected in newborns, which could allow treatment to prevent its ill effects. Using the blood spots on filter paper system that Dr. Guthrie developed in the early 1960s for PKU, NICHD-supported researchers developed a new screening technique that could reliably measure thyroid hormone and thyroid-stimulating hormone, the two main hormone markers of CH. This reliable and inexpensive test allowed for mass screening.
Early studies on the effectiveness of the screening test, supported by the Institute, showed that children born with CH detected at birth using the new screening test, and who received appropriate levels of thyroid hormone, had the same intellectual capabilities as their siblings who did not have the condition.
As a result of NICHD research, every state screens all newborns for CH so it is detected immediately and treatment begins right away to prevent the disabilities previously associated with CH. These individuals continue to receive the simple, yet effective treatment every day of their lives, eliminating any damage from the condition.