What is Cretinism ?
Cretinism is a congenital form of deficiency of thyroid hormones, retarding mental and physical growth.

A cretin is a person affected by cretinism. This term has come to be regarded as insulting in the general population, although it is appropriate within technical settings.

Cretinism results from thyroid hormone deficiency. Thyroid hormones have permissive growth effects on body tissues such as muscular and neuronal tissue. A person afflicted with cretinism has severe physical and mental retardation. Often times he/she will have the physical stature of a child, when in fact the person is much older. Other symptoms may include slurred speech and movement, a protruding abdomen, and waxy skin.

Cretinism can manifest in a number of ways. If a person is born lacking a thyroid gland he/she will be affected. Also, it can develop through iodine deficiency. For this reason, cretinism has historically been more common in areas where the soil is deficient in iodine.

If it is treated early with thyroid hormones and trace iodine supplementation of the diet, significant improvement can be seen.

What is congenital hypothyroidism ?
Congenital hypothyroidism is a condition of thyroid hormone deficiency present at birth. Approximately 1 in 4000 newborn infants has a severe deficiency of thyroid function, while even more have mild or partial degrees. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent mental retardation. Treatment consists of a daily dose of thyroid hormone ( thyroxine) by mouth. Because the treatment is simple, effective, and inexpensive, nearly all of the developed world practices newborn screening to detect and treat congenital hypothyroidism in the first weeks of life.

1 Causes
Around the world, the most common cause of congenital hypothyroidism is iodine deficiency, but in most of the developed world and areas of adequate environmental iodine, cases are due to a mixture of known and unknown causes. Most commonly there is a defect of development of the thyroid gland itself, resulting in an absent (athyreosis) or underdeveloped (hypoplastic) gland. A hypoplastic gland may develop higher in the neck or even in the back of the tongue. A gland in the wrong place is referred to as ectopic, and an ectopic gland at the base or back of the tongue is a lingual thyroid. Some of these cases of developmentally abnormal glands result from genetic defects, and some are "sporadic," with no identifiable cause.

Congenital hypothyroidism can also occur due to genetic defects of thyroxine or triiodothyronine synthesis within a structurally normal gland. Among specific defects are thyrotropin ( TSH) resistance, iodine trapping defect, organification defect, thyroglobulin, and iodotyrosine deiodinase deficiency. In a small proportion of cases of congenital hypothyroidism, the defect is due to a deficiency of thyroid stimulating hormone, either isolated or as part of congenital hypopituitarism.

In some instances, hypothyroidism detected by screening may be transient. The most common cause of this is the presence of maternal antibodies which temporarily impair thyroid function for several weeks.
Cretinism is an old term for the state of mental and physical retardation resulting from untreated congenital hypothyroidism, usually due to iodine deficiency from birth because of low iodine levels in the soil and local food sources. The term, like so many other 19th century medical terms, acquired pejorative connotations as it became used in lay speech. It is now rarely used by physicians.

2 Diagnostic evaluation
In the developed world, nearly all cases of congenital hypothyroidism are detected by the newborn screening program. These are based on measurement of TSH or thyroxine.

  Thyroid Gland

  Healthcare Provider

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