Genetic disorders of the thyroid

Genetic factors play an important role in the etiology of many thyroid diseases. Almost all types of genetic disturbance have been reported to be operative in thyroid disorders, including single gene defects (autosomal, x-linked, dominant and recessive modes of inheritance), polygenic or multifactorial inheritance (owing to the interaction of multiple genes and environmental factors), as well as chromosomal aberrations. Knowledge of these genetic factors may assist the clinician in determining the correct diagnosis, identifying other family members at risk for the disease, and providing informative genetic counseling. In this review, the genetic forms of thyroid disease are discussed and classified chiefly on the basis of the type of disturbance in thyroid function, as this is the manner in which the patient presents himself to the clinician.