Congenital iodine deficiency syndrome protruding abdomen. Dwarfism may also be caused by malnutrition or other hormonal deficiencies, such as insufficient growth hormone secretion, hypopituitarism, decreased secretion of growth hormone-releasing hormone, deficient growth hormone receptor activity and downstream causes, such as insulin-like growth factor 1 (IGF-1) deficiency. Sporadic and genetic congenital iodine deficiency syndrome results from abnormal development or growth of the foetal thyroid gland. This type of congenital iodine deficiency has been almost completely eliminated in developed countries by early diagnosis by newborn screening schemes followed by lifelong treatment with thyroxine (T4). Thyroxine must be dosed as tablets only, even to newborns, as the
Isotopes of iodine for the so-called iodine pit phenomenon. In addition to commercial production, I (half-life 8 days) is one of the common radioactive fission-products of nuclear fission, and is thus produced inadvertently in very large amounts inside nuclear reactors. Due to its volatility, short half-life, and high abundance in fission products, I, (along with the short-lived iodine isotope I from the longer-lived Te with a half-life of 3 days) is responsible for the largest part of radioactive contamination during the first week after accidental environmental contamination from the radioactive waste from a nuclear power plant. Radioisotopes of iodine are called radioactive iodine