These are present in some quantity in almost all kinds of food, but in particular, protein-rich foods such as dairy products, meat, fish, soy, gluten, eggs, nuts, whole grains, seeds, avocados, algae, edible seaweed, beans, and pulses. Mutation in any of these genes reduces or eliminates the function of the enzyme complex, preventing the normal breakdown of isoleucine, leucine, and valine. As a result, these amino acids and their by-products build up in the body. Because high levels of these substances are toxic to the brain and other organs, this accumulation leads to the serious medical problems associated with maple syrup urine disease.This condition has an autosomal recessive inheritance pattern, which means the defective gene is located on an autosome, and two copies of the gene – one from each parent – must be inherited to be affected by the disorder. The parents of a child with an autosomal recessive disorder are carriers of one copy of the defective gene, but are usually not affected by the disorder. Pathophysiology
MSUD is a metabolic disorder caused by a deficiency of the branched-chain alpha-keto acid dehydrogenase complex (BCKAD), leading to a buildup of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products (ketoacids) in the blood and urine. The buildup of these BCAAS will lead to the maple syrup odor that is associated with MSUD. The BCKAD complex begins by breaking down leucine, isoleucine, and valine through the use of branch-chain aminotransferase into their relevant α-ketoacids.
There are several types, including:
X-linked chronic granulomatous disease (CGD)
autosomal recessive cytochrome b-negative CGD
autosomal recessive cytochrome b-positive CGD type I
autosomal recessive cytochrome b-positive CGD type II
atypical granulomatous disease

Treatment
Management of chronic granulomatous disease revolves around two goals: 1) diagnose the disease early so that antibiotic prophylaxis can be given to keep an infection from occurring, and 2) educate the patient about his or her condition so that prompt treatment can be given if an infection occurs. Antibiotics
Physicians often prescribe the antibiotic trimethoprim-sulfamethoxazole to prevent bacterial infections. This drug also has the benefit of sparing the normal bacteria of the digestive tract. Fungal infection is commonly prevented with itraconazole, although a newer drug of the same type called voriconazole may be more effective. The use of this drug for this purpose is still under scientific investigation. Immunomodulation
Interferon, in the form of interferon gamma-1b (Actimmune) is approved by the Food and Drug Administration for the prevention of infection in CGD. It has been shown to reduce infections in CGD patients by 70% and to decrease their severity. Although its exact mechanism is still not entirely understood, it has the ability to give CGD patients more immune function and therefore, greater ability to fight off infections. This therapy has been the standard treatment for CGD for several years. Hematopoietic stem cell transplantation (HSCT)
Hematopoietic stem cell transplantation from a matched donor is curative although not without significant risk. Prognosis
There are currently no studies detailing the long term outcome of chronic granulomatous disease with modern treatment.