Cretinism, also known as congenital hypothyroidism, is a condition caused by a deficiency of thyroid hormones while a fetus is developing in the womb or shortly after birth. In developing countries, the cause is usually a lack of iodine, but in developed countries, this deficiency is usually caused by a defect in the development of the thyroid gland itself, though it has also been linked to an inherited condition that interrupts the synthesis of thyroxine. Thyroxine is a hormone comprised primarily of iodine that regulates the rate of cellular oxidation. Another cause has been attributed to antithyroid medications taken by the mother during pregnancy, but this cause is infrequent.
Left untreated, cretinism can stunt growth to the degree of dwarfism and causes severe mental retardation. Without a properly functioning thyroid, bones and muscles will degenerate, as the thyroid has a key role in cellular metabolism and development. In short, iodine must be present for the thyroid to function properly, and the thyroid must function correctly for cells to develop. If individual cells don't develop, they cannot form strong bones and muscles. So, cretinism, or congenital hypothyroidism, is the result of any interruption in this cycle.
Newborn infants suffering from cretinism may be of normal height and weight, but symptoms in babies who are not breastfed generally show up in the first few months. Breastfed babies may have a delay in symptoms due to thyroid hormones found in breast milk. Many will have respiratory issues, feeding difficulties, appear inactive, and suffer from jaundice. They may also sleep excessively, seldom cry, and have difficulty breathing. It is very important to seek treatment as soon as possible, before increasing mental impairment becomes irreversible.
Diagnosis is made by testing hormone levels in infants, and if tests indicate an issue, a thyroid scan will be performed to assess the thyroid gland. If tests confirm cretinism, patients receive hormone replacement therapy in the form of oral thyroxine. Ideally, this treatment would be started within the first few weeks of life, and the treatment will continue for a lifetime, with doses reduced or increased as appropriate.
At one time, the term cretin was used to describe sufferers of cretinism. The medical community has since abandoned the term as it has taken on negative connotations. Like idiot and dumb, this medical term found its way into mainstream lingo and is used as an insult, so it is best to leave it out of one's vocabulary when referring to a sufferer of cretinism.