Cretinism' is a disease that occurs in children and infants due to lack of thyroid hormone. The thyroid gland located in front of the neck secretes thyroid hormones which control the speed at which the body's chemical functions i.e. metabolism proceeds. Almost every cell in the body, from those in the brain to those in the feet, responds to the hormone. To produce thyroid hormones, the thyroid gland needs iodine. Iodine is an essential trace element necessary for the synthesis of thyroid hormones. Iodine is found in the earth's crust in sparse amount in the form of iodide. As iodide is soluble, soils are lowest in iodine where there is plenty of rainfall or where glaciers have melted and leached the iodine out of the soil.

Dr. Fahmida Tofail, Asst. Scientist, ICDDR,B sharing her experience states. 'A child of 7 months was brought to us because of diarrheoa, whilst going through the birth history we discovered that she had been born in 36 weeks, her crying was unusually delayed and she was suffering from prolonged jaundice as well. There were other complains like constipation, lethargy, hoarse crying, no interest in feeding etc. The child had wide spaced eyes, protruded tongue, short neck, wide spaced nipples, umbilical hernia and a disproportionate body ratio. After checking her thyroid profile we found that the child was suffering from hypothyroidism. Her mental development corresponded to a 1 month old child. Now if a health screening was done soon after birth this very child could have leaded a normal life'. According to Dr. Tofail 'Birth screening is absolutely necessary and should be done within 7 days and the test should be repeated if necessary. For each week delay in treatment the IQ of a child is affected by 1 to 2 points.'

Cretinism, results from a congenital defect like absence of a thyroid, presence of only the rudimentary gland or from the inability of the gland to produce thyroxine. Cretinism can cause serious retardation of physical and mental development, growth is stunted and physical stature resembles that of a dwarf. Poor length growth is usually apparent from the very first year of life and the adult stature ranges from 1 to 1.6 metres depending on the severity of the disease, sex and other genetic factors. Sometimes it may be so severe that the person is non verbal and has to depend on others for basic care. Skin becomes thick, flabby and waxy in colour, nose is flattened, abdomen protrudes and there is a general slowness in movement and speech, heart rate is slower and the patient suffers from constipation. Bone maturity and puberty is delayed; ovulation is hampered and infertility is common in these cases. In pregnant mothers the deficiency results in anaemia, still birth and abortion. Cretinism has affected many people around the world and continues to be a major public health problem in many countries.

However, if discovered early and with sufficient iodine intake throughout life, growth may become normal and mental capacity may be greatly improved. Cretinism is one of the most prevalent preventable causes of impaired intellectual development in the world today. Children with iodine deficiency have intelligent quotient that is less by 25 points than the normal children. Consumption of iodised salt is necessary for a healthy life. Therefore it is high time we start to combat cretinism in children by proper health campaigns, socio-economic and cultural programmes.

It is possible to completely eliminate cretinism in infants by early diagnosis with the help of newborn screening followed by lifelong treatment with thyroxine (T4). Dr. Tofail says 'All hospitals should provide the facilities of new born screening.' Cretinism can also be prevented by iodine supplementation before conception. Iodine supplementation during the second trimester of pregnancy is beneficial in reducing the prevalence of moderate and severe neurologic abnormalities. Findings indicate that supplementation of iodine before the end of second trimester helps to protect the fetal brain from the effects of iodine deficiency. However, it is advised that in case of deficiency iodine intake should be started before pregnancy and continued on a regular basis.

Use of iodized salt is another simple and effective way of providing iodine in the diet, which help in reducing the prevalence of goitre and progressive decrease in endemic cretinism. Prophylaxis and therapy are other methods that can be achieved effectively by injecting iodized oil by intramuscular injection or orally. Moreover necessary steps should be taken to ban the sale of non-iodized salt and strictly monitor the quality of salt sold to consumers. Dr. Tofail says 'There is this easy way of knowing if your salt has iodine in it; just squeeze a bit of lemon in your salt - if it turns purple then there is iodine in it.'

Hypothyroidism may develop at any point in lifespan. Infants can be born with hypothyroidism, and hypothyroidism can develop in children and adults of any age. The treatment for it is also simple. The key is to supply the body with the thyroid hormone that is not being produced and released by the thyroid gland. Most of the children with cretinism will require thyroid hormone replacement therapy for the rest of their lives and the success of the therapy can also be monitored by blood tests that can be done throughout adult life. But, it is important that experienced physicians oversee treatment, as the body's need for thyroid hormone varies over the course of childhood and puberty.

Cretinism or hypothyroidism can be easily avoided. Every child can grow up and lead a normal and healthy life; all we have to do is be informed and aware!