Cretinism: Growth retardation, developmental disorders, and other aberrant traits are all symptoms of congenital hypothyroidism (under activity of the thyroid gland at birth). Cretinism can be caused by a lack of iodine in the mom’s diet when she is pregnant. Because the afflicted were intellectually handicapped and incapable of committing sin, the word cretin was taken from the French word chrétien, which literally means “Christian” or “Christ-like.” This medical issue affects persons in different ways depending on their age. Hypothyroidism causes mental and physical impairment in children, resulting in this syndrome.
A brief outline
TBG (Thyroxine binding globulin) levels may be raised during maternal hypoestrogenism, while total T4 (thyroxine or tetraiodothyronine) and T3 (triiodothyronine) levels may be normal. A high TSH level is also caused by a lack of feedback. In cretinism, prompt diagnosis and therapy are critical since any delay in early replacement might result in irreparable damage. Neonatal cretinism could also be triggered by mother hypothyroidism. Treatment of hyperthyroidism with antithyroid medications or radioactive iodine might lead to hypothyroidism. The hormone replacement will have an immediate effect. The breakdown of thyroid development or a shortfall in hormone production, known as sporadic cretinism, or extreme iodine shortage, known as endemic cretinism, causes this illness.
Examples of Cretinism
There are two types of cretinism as far as medicine is concerned:
- Congenital Cretinism: In an iodine-deficient endemic area, the rate of congenital cretinism is 1:3000 to 1:4000. This is mostly due to a deficiency in the genes that code for thyroglobulin, diiodotyrosine deiodinase, thyroid-stimulating hormone, as well as other enzymes involved in thyroid hormone synthesis. This type of hypothyroidism is also known as non-goitrous hypothyroidism or congenital hypothyroidism (CHNG). CHNG1 to CHNG5 are several forms of congenital hypothyroidism genes. The most common inborn endocrine condition is non-goitrous congenital hypothyroidism.
- Endemic Cretinism: The recommended daily iodine intake for individuals is 150 grams. This type of cretinism primarily affects children who live in iodine-deficient areas, and it is not treated with iodine or thyroid hormone supplementation to restore normal thyroid hormone levels throughout childhood. Hypothyroidism has been diagnosed in the moms of endemic cretinism children in the majority of cases (Maternal hypothyroidism). In some situations, radioactive iodine exposure during pregnancy may be the cause. During pregnancy, antithyroid medications or sulphonamides should be avoided. Giving birth to cretinism neonates could be a risk factor if iodine consumption was as low as 25 mcg/day during pregnancy.
- Neurological cretinism: Retarded growth, deaf-mutism, muscular spasticity, and severe mental retardation with a squint are all symptoms of neurological cretinism.
- Myxedematous cretinism: Retarded growth, incomplete maturity of facial expression, and myxedematous cretinism are all symptoms of myxedematous cretinism. Skin that is thickened and dry Hair that is little and dry, as well as eyelashes and eyebrows, Hypothyroidism can cause milder mental impairment than neurological cretinism, as well as delayed sexual maturation and other clinical symptoms.
The following are the main causes of cretinism:
- Thyroid gland absence and thyroid gland failure to generate thyroid hormone (congenital cretinism or congenital iodine deficiency syndrome).
- Dietary iodine insufficiency (Endemic cretinism).
- According to the pathophysiological conditions, an optimal level of maternal thyroid function is essential for appropriate foetal growth. The only source of foetal brain growth for the foetus that crosses the placenta is a maternal thyroid hormone.
- In the fetal and neonatal phases, thyroid hormone is important for the growth, branching, and myelination of CNS neuronal cells. As a result, the absence of thyroid hormone during these phases would have a significant impact on the development of the central nervous system.
- A prenatal screening test can detect congenital cretinism including severe hypothyroidism in the first month of life.
- Thyroid scan with technetium (Tc– 99m pertechnetate).
- Test for radioactive iodine (RAIU)
- Guthrie’s test is a postnatal blood spot test.
- Thyroid binding globulin (TBG) and TSH levels in the blood are elevated.
- T3 levels in the blood are high, whereas T4 levels are low.
Significance of cretinism in NEET exam
Experts have produced materials for the NEET test that will help students understand the ideas of Human Health and Diseases. The theories on diseases and their causes are presented in this chapter. Students will study diseases and how they affect vital areas of human physiology. Solutions provide a quick overview of the subject content and help you save time when studying for the exam.
Also read: Important Topic Of Biology: Thyroid
Question 1: What can be done to prevent cretinism?
Ans: Around one billion individuals worldwide are in danger of iodine deficiency, which can all be prevented with proper maternal and neonatal iodine nutrition. Iodized salt is the most used prophylactic carrier, but other options include iodized vegetable oil, iodized water, and iodine tablets. Iodine shortage in pregnant women can be hazardous to the developing fetus. As a result, it is recommended that women consume at least 220 micrograms of iodine every day to prevent cretinism.
Q. What’s the difference between myxoedema and congenital hypothyroidism?
Ans: The difference between them is that myxoedema is a disorder in which an adult’s thyroid glands are dormant. Low thyroid hormone levels can also induce skin abnormalities, which is referred to as hypothyroidism. The term “congenital hypothyroidism” was coined to describe this condition that occurs at birth.
Q. What causes mental retardation incretins?
Ans: Iodine deficiency is the most prevalent preventable cause of mental impairment on the planet. According to this viewpoint, anyone who is lacking in iodine is at risk of having an inferior cognitive and psychomotor function.