Thyroid hormones which causes the thyroid to enlarge (the resulting medical condition is called "endemic colloid goitre"; see goitre). This has the effect of increasing the thyroid's ability to trap more iodide, compensating for the iodine deficiency and allowing it to produce adequate amounts of thyroid hormone. Most of the thyroid hormone circulating in the blood is bound to "transport protein"s. Only a very small fraction of the circulating hormone is free (unbound) and biologically active, hence measuring concentrations of free thyroid hormones is of great diagnostic value. When thyroid hormone is bound, it is not active, so the amount of free
Acyl-CoA oxidase deficiency Acyl-CoA oxidase deficiency Acyl-CoA oxidase deficiency (ACOX1 deficiency) is a rare disorder that leads to significant damage and deterioration of nervous system functions (neurodegeneration). It is caused by pathogenic variants in "ACOX1", which codes for the production of an enzyme called peroxisomal straight-chain acyl-CoA oxidase (ACOX1). This specific enzyme is responsible for the breakdown of very long chain fatty acids (VLCFAs). Defective function of the ACOX1 enzyme prevents proper breakdown of these VLCFAs, leading to accumulation and interference with the nervous system. Acyl-CoA oxidase deficiency affects a person from birth, and most newborns affected with this condition will not survive