The information stored in the mtDNA is used to produce several of the enzymes essential to the production of ATP.Between 20 and 25 percent of Leigh syndrome cases are caused by mutations in mitochondrial DNA. The most common of these mutations is found in 10 to 20 percent of Leigh syndrome and occurs in MT-ATP6, a gene that codes for a protein in the last complex of the oxidative phosphorylation chain, ATP synthase, an enzyme that directly generates ATP. Without ATP synthase, the electron transport chain will not produce any ATP. The most common MT-ATP6 mutation found with Leigh syndrome is a point mutation at nucleotide 8993 that changes a thymine to a guanine. This and other point mutations associated with Leigh syndrome destabilize or malform the protein complex and keep energy production down in affected cells. Several mitochondrial genes involved in creating the first complex of the oxidative phosphorylation chain can be implicated in a case of Leigh syndrome, including genes MT-ND2, MT-ND3, MT-ND5, MT-ND6 and MT-CO1.Mitochondrial DNA is passed down matrilineally in a pattern called maternal inheritance — a mother can transmit the genes for Leigh syndrome to both male and female children, but fathers cannot pass down mitochondrial genes. Nuclear DNA mutations
Nuclear DNA comprises most of the genome of an organism and in sexually reproducing organisms is inherited from both parents, in contrast to mitochondrial DNAs maternal pattern of inheritance. Leigh syndrome caused by nuclear DNA mutations is inherited in an autosomal recessive pattern.
Ravulizumab, sold under the brand name Ultomiris, is a humanized monoclonal antibody complement inhibitor medication designed for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome. It is designed to bind to and prevent the activation of Complement component 5 (C5).Paroxysmal nocturnal hemoglobinuria is characterized by red blood cell destruction, anemia (red blood cells unable to carry enough oxygen to tissues), blood clots, and impaired bone marrow function (not making enough blood cells). In paroxysmal nocturnal hemoglobinuria, proteins known as the complement system, which is part of the immune system, become overactive because of a genetic mutation and start to attack the patients own red blood cells. Ravulizumab, is a monoclonal antibody (a type of protein) designed to attach to the C5 protein, which is part of the complement system. By attaching to the C5 protein, the medicine blocks its effect and thereby reduces the destruction of red blood cells.The most common side effects are upper respiratory tract infection (nose and throat infection), nasopharyngitis (inflammation of the nose and throat) and headache. The most serious side effect is meningococcal infection, a bacterial infection caused by Neisseria meningitidis that can cause meningitis and sepsis.