Congenital iodine deficiency syndrome degree of iodine deficiency was milder and manifested primarily as thyroid enlargement rather than severe mental and physical impairment. In Switzerland, for example, where soil does not contain a large amount of iodine, cases of congenital iodine deficiency syndrome were very abundant and even considered genetically caused. As the variety of food sources dramatically increased in Europe and North America and the populations became less completely dependent on locally grown food, the prevalence of endemic goitre diminished. The early 20th century saw the discovery of the relationships of neurological impairment with hypothyroidism due to iodine deficiency. Both have been largely
Mitochondrial trifunctional protein deficiency mitochondrial trifunctional protein deficiency that may begin "after" infancy include hypotonia, muscle pain, a breakdown of muscle tissue, and a loss of sensation in the extremities called peripheral neuropathy. Some who have MTP deficiency show a progressive course associated with myopathy, and recurrent rhabdomyolysis. The genetics of mitochondrial trifunctional protein deficiency is based on mutations in the HADHA and HADHB genes which cause this disorder. These genes each provide instructions for making part of an enzyme complex called mitochondrial trifunctional protein. This enzyme complex functions in mitochondria, the energy-producing centers within cells: mitochondrial trifunctional protein contains three enzymes that each