Congenital iodine deficiency syndrome is a medical condition present at birth marked by impaired physical and mental development, due to insufficient thyroid hormone (hypothyroidism) often caused by insufficient dietary iodine during pregnancy. It is one cause of underactive thyroid function at birth, called congenital hypothyroidism, historically referred to as cretinism (obsolete). If untreated, it results in impairment of both physical and mental development. Symptoms may include goiter, poor length growth in infants, reduced adult stature, thickened skin, hair loss, enlarged tongue, a protruding abdomen; delayed bone maturation and puberty in children; and mental deterioration, neurological impairment, impeded ovulation, and infertility in adults.In developed countries, thyroid function testing of newborns has assured that in those affected, treatment with the thyroid hormone thyroxine is begun promptly. This screening and treatment have virtually eliminated the consequences of the disease. Signs and symptoms
Iodine deficiency causes gradual enlargement of the thyroid gland, referred to as a goiter. Poor length growth is apparent as early as the first year of life. Adult stature without treatment ranges from 100 to 160 cm (3 ft 3 in to 5 ft 3 in), depending on severity, sex, and other genetic factors. Other signs include thickened skin, hair loss, enlarged tongue, and a protruding abdomen. In children, bone maturation and puberty are severely delayed. In adults, ovulation is impeded and infertility is common.Mental deterioration is common. Neurological impairment may be mild, with reduced muscle tone and coordination, or so severe that the person cannot stand or walk.
As the variety of food sources dramatically increased in Europe and North America and the populations became less completely dependent on locally grown food, the prevalence of endemic goitre diminished. This is supported by a 1979 WHO publication which concluded that "changes in the origin of food supplies may account for the otherwise unexplained disappearance of endemic goitre from a number of localities during the past 50 years".The early 20th century saw the discovery of the relationships of neurological impairment with hypothyroidism due to iodine deficiency. Both have been largely eliminated in the developed world. Terminology
The term cretin was originally used to describe a person affected by this condition, but, as with words such as spastic and lunatic, it underwent pejoration and is now considered derogatory and inappropriate. Cretin became a medical term in the 18th century, from an Occitan and an Alpine French expression, prevalent in a region where persons with such a condition were especially common (see below); it saw wide medical use in the 19th and early 20th centuries, and was a "tick box" category on Victorian-era census forms in the UK. The term spread more widely in popular English as a markedly derogatory term for a person who behaves stupidly. Because of its pejorative connotations in popular speech, current usage among health care professionals has abandoned the noun "cretin" referring to a person. The noun cretinism, referring to the condition, still occurs in medical literature and textbooks but its use is waning.The etymology of cretin is uncertain. Several hypotheses exist.