It affects the nervous syste and caused by lack of thyroid hormones from the mother during third to sixth month of pregnancy, the severe lack of iodine means the fetus is unable to produce thyroid hormones during this period, which is very dangerous as during this period the brain is developing the ability to hear and perform other motor functions. Neurologic cretins may not be hypothyroid (lack of thyroid hormones) later in life if they receive sufficient iodine that makes the thyroid produce sufficient thyroid hormones. However damage done during development of brain is irreversible.
Myxedematous Cretinism has a less ascetic degree of mental detainment than the neurological cretin. It has all the countenance of dreadfully stern hypothyroidism exhibit since premature life, as in non realised sporadic congenital hypothyroidism, life-threatening growth retardation, unfinished maturation of the features including the naso-orbital configuration, atrophy of the mandibles, intumescent features, myxedematous, thickened and dry skin, dry and infrequent hair, eyelashes and eyebrows and much delayed sexual maturation. Other signs may include inspissate skin and a protruding abdomen.