Paediatrics => Cretinism
Cretinism, deficiency disease caused by congenital absence of thyroxine, a hormone secreted by the thyroid gland, and characterized by disorders of mental and physical development. Cretins have dwarfed bodies, with curvature of the spine and a pendulous abdomen. Their limbs are distorted, their features heavy, and their hair is harsh and scanty. Mental development is affected throughout life. An adult cretin may reach the intelligence of only a four-year-old child. Research has revealed that when an animal or human infant is born with a deficiency of thyroxine, the neurons (nerve cells) in the brain do not develop the multiple branches that normally form the brain's complex network. Treatment of adult cretins with thyroxine or thyroid extract results in some improvement; early treatment in infancy results in cure of the disease and normal development of the individual, provided the treatment is continued throughout life. A screening test for thyroxine levels in the blood of newborn infants is offered routinely in many hospitals. Treatment is sometimes begun prenatally, for instance, when a mother suffers from severe goitre, a disease of the thyroid.
Endemic cretinism is associated with goitre throughout the world, especially in certain valleys of the Alps and Pyrenees mountains, and in Syria, India, and China. Families moving into such areas tend to develop goitre in the first generation and cretinism in the second and succeeding generations. Public health measures, including the addition of iodine to public water supplies, have proved beneficial in reducing the incidence of goitre and cretinism in certain areas. Iodine is an essential building block of thyroxine.