Generalized thyroid hormone resistance (GTHR) otherwise known as Refetoff Syndrome, is an inherited condition that causes some tissues to be less responsive to thyroid hormone. Symptoms of GTHR may include enlarged thyroid gland, exophthalmos (bulging of one or both eyes), feeling tired, being overweight, and having a fast heart rate. Some people with GTHR may only display some symptoms or none at all if they have partial GTHR. Subtler symptoms of GTHR include delayed speech development, deafness, mental disability, ear/nose/throat infections in children, and delayed skeletal maturation.
GTHR is caused by one of two mutations made to the same gene, the thyroid hormone receptor gene (THRB). Genes are units of DNA that hold the codes for creating proteins necessary for life and normal bodily processes. One mutation is autosomal dominant, which is the more common type, and one is autosomal recessive, which is less common.
Diagnosis of GTHR mainly involves thyroid function tests to check for levels of thyroid hormones and to rule out other possible disease; usually, thyroid hormone levels will be high in GTHR patients. GTHR may also be confirmed with genetic testing to verify the THRB mutation and identify whether it is dominant or recessive.
GTHR is difficult to treat, as lowering thyroid hormone levels for the whole body may help some tissues while hurting others. Therefore, targeted treatment is necessary. Patients who experience fast heartrate as a result of GTHR may be given drugs to lower it. Similarly, some GTHR patients report symptomatic diarrhea, which may also be treated. Medications may be given that mimic the actions of thyroid hormone in different tissues, which is successful in some cases.
If you or a family member has been diagnosed with GTHR, speak with your doctor about the most current treatment options. Support groups may also be available for further resources and information.
Description Last Updated: Aug 21, 2018