Hypothyroidism: Underactive thyroid activity.
Aplasia / agenesis: Absence of an organ due to failure of development.
Dysgenesis/hypoplasia: Defective or incomplete development.
Endocrine: A regulatory system comprised of the endocrine glands that controls vital body functions such as metabolic activity, growth, and reproduction.
Hormone: A chemical substance produced in an organ, which, carried to an associated organ by the blood stream, influences its functional activity.
Antibody: It is a protein complex used by immune system to identify and neutralize foreign objects like bacteria and viruses.
Thyroid scan: An image obtained from the thyroid gland after oral administration of radioiodine or Technetium.
Ectopic: Located away from normal position.
Endemic: A disease that is constantly present to a greater or lesser degree in people of a certain class or in people living in a particular location.
T3 (liothyronine sodium), T4 (levothyroxine sodium): Thyroid hormones.