Nemaline myopathy
Nemaline myopathy was first described in 1963 and is the most common congenital myopathy. It is characterized by generalized muscle weakness and low muscle tone. In its severest form, affected babies often die from respiratory failure. To date, 9 gene mutations have been found to cause nemaline myopathy. 6 of the identified genes are associated with the actin filament, which is the basis for muscle contraction. Histologically, nemaline rods stain red with Gomoris trichrome and are mostly seen in the subsarcolemmal region of muscle fibres. Nemaline rods have also been observed in the intermyofibrillar region of muscle fibres and within the nucleus. Nemaline myopathy is an autosomal dominant and sometimes an autosomal recessive genetic disorder. Sporadic cases have also been described. Myotubular myopathy
Myotubular myopathy, also known as centeronuclear myopathy, is recognized by pain during exercise and difficulty walking. People affected by this disease typically are wheelchair-reliant by middle adulthood, have weakness in the muscles involved in eye movement, nerve function disorders, and some form of intellectual disability. Myotubular myopathy is very rare, with less than 50 families currently affected. Genetically, myotubular myopathy can have two causes: autosomal dominant and autosomal recessive. When caused by a mutation in the DNM2 gene, the disorder is autosomal dominant, meaning it can be passed on by one mutated gene. When the mutation takes place in the BIN1 gene, the disease is instead autosomal recessive, and both genes must be mutated for the disease to be inherited. Autosomal recessive onset is most common.
Due to the excess activity of FGF23, phosphate levels in the blood are abnormally low, which affects the constitution of bone. Thus, burosumab is designed to bind to the FGF23 receptor and inhibit the excess activity of the FGF23 hormone within the body.While burosumab is effective for the treatment of X-linked hypophosphatemia, the National Institute for Health and Care Excellence in England and Wales initially raised concerns regarding the incremental cost-effectiveness of the new treatment but the drug is available through a simple discount scheme. History
This drug was developed by Ultragenyx and is in a collaborative license agreement with Kyowa Hakko Kirin. References
External links
"Burosumab". Drug Information Portal. U.S. National Library of Medicine.