Peripheral Hypothyroidism

Peripheral hypothyroidism is a type of permanent congenital hypothyroidism (see this term), a permanent thyroid hormone deficiency that is present from birth, that results from peripheral defects in thyroid hormone metabolism.

Epidemiology

Prevalence is unknown.

Etiology

Peripheral hypothyroidism may be caused by peripheral resistance to the action of thyroid hormone (see this term). Ninety percent of these cases are due to dominantly inherited mutations in genes encoding for thyroid hormone receptor beta. The majority of these individuals have normal thyroid function but some hypothyroid individuals have been described. Peripheral hypothyroidism may also be caused by defects in thyroid hormone transport, such as in Allan-Herndon-Dudley syndrome (see this term) where X-linked peripheral hypothyroidism is associated with mental retardation and neurologic abnormalities including quadriplegia.