glutaric acidemia type 2

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Mutations in the ETFA, ETFB, and ETFDH genes cause glutaric acidemia type II. Mutations in these genes result in a deficiency in one of two enzymes that normally work together in the mitochondria, which are the energy-producing centers of cells. The ETFA and ETFB genes encode two subunits of the enzyme electron transfer flavoprotein, while the ETFDH gene encodes the enzyme electron-transferring-flavoprotein dehydrogenase. When one of these enzymes is defective or missing, the mitochondria cannot function normally, partially broken-down proteins and fats accumulate in the cells and damage them; this damage leads to the signs and symptoms of glutaric acidemia type II.

This condition is inherited in an autosomal recessive pattern, which means the defective gene is located on an autosome, and two copies of the gene – one from each parent – are needed to inherit the disorder. The parents of an individual with an autosomal recessive disorder are carriers of one copy of the defective gene, but do not show signs and symptoms of the disorder themselves.{{cn|date=October 2021}}

Glutaric acidemia type 2 often appears in infancy as a sudden metabolic crisis, in which acidosis and low blood sugar (hypoglycemia) cause weakness, behavior changes, and vomiting. There may also be enlargement of the liver, heart failure, and a characteristic odor resembling that of sweaty feet. Some infants with glutaric acidemia type 2 have birth defects, including multiple fluid-filled growths in the kidneys (polycystic kidneys). Glutaric acidemia type 2 is a very rare disorder. Its precise incidence is unknown. It has been reported in several different ethnic groups.{{cn|date=October 2021}}

It is important for patients with MADD to strictly avoid fasting to prevent hypoglycemia and crises of metabolic acidosis;{{cite web |title=Multiple acyl-CoA dehydrogenase deficiency |url=https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=26791 |website=Orphanet |publisher=INSERM and the European Commission |access-date=30 August 2018}}{{cite web |title=Glutaric acidemia type II |url=https://rarediseases.info.nih.gov/diseases/6523/glutaric-acidemia-type-ii |website=Genetic and Rare Diseases Information Center (GARD) |publisher=National Institutes of Health National Center for Advancing Translational Sciences |access-date=30 August 2018 |archive-date=21 September 2021 |archive-url=https://web.archive.org/web/20210921210424/https://rarediseases.info.nih.gov/diseases/6523/glutaric-acidemia-type-ii |url-status=dead }} for this reason, infants and small children should eat frequent meals. Patients with MADD can experience life-threatening metabolic crises precipitated by common childhood illnesses or other stresses on the body, so avoidance of such stresses is critical. Patients may be advised to follow a diet low in fat and protein and high in carbohydrates, particularly in severe cases. Depending on the subtype, riboflavin (100-400 mg/day), coenzyme Q10 (CoQ10), L-carnitine, or glycine supplements may be used to help restore energy production. Some small, uncontrolled studies{{cite journal |vauthors=Gautschi M, Weisstanner C, Slotboom J, Nava E, Zürcher T, Nuoffer JM |title=Highly efficient ketone body treatment in multiple acyl-CoA dehydrogenase deficiency-related leukodystrophy |journal=Pediatr Res |date=January 2015 |volume=77 |issue=1 |pages=91–8 |doi=10.1038/pr.2014.154 |pmid=25289702 |doi-access=free }}{{cite journal |vauthors=Van Rijt WJ, Heiner-Fokkema MR, du Marchie Sarvaas GJ, Waterham HR, Blokpoel RG, van Spronsen FJ, Derks TG|title=Favorable outcome after physiologic dose of sodium-D,L-3-hydroxybutyrate in severe MADD |journal=Pediatrics |date=October 2014 |volume=134 |issue=4 |pages=e1224-8 |doi=10.1542/peds.2013-4254 |pmid=25246622 |s2cid=16829114 |url=http://pediatrics.aappublications.org/content/134/4/e1224.long |access-date=30 August 2018|url-access=subscription }}{{cite journal |vauthors=Van Hove JL, Grünewald S, Jaeken J, Demaerel P, Declercq PE, Bourdoux P, Niezen-Koning K, Deanfeld JE, Leonard JV |title=D,L-3-hydroxybutyrate treatment of multiple acyl-CoA dehydrogenase deficiency (MADD) |journal=The Lancet |date=26 April 2003 |volume=361 |issue=9367 |pages=1433–5 |doi=10.1016/S0140-6736(03)13105-4 |pmid=12727399 |s2cid=25397192 }} have reported that racemic salts of beta-hydroxybutyrate (one of the ketone bodies) were helpful in patients with moderately severe disease; further research is needed.

• Glutaric acidemia type 1
• Riboflavin-responsive exercise intolerance - similar in biochemical features, also responsive to riboflavin
• Metabolic myopathy

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This article incorporates public domain text from [http://ghr.nlm.nih.gov The U.S. National Library of Medicine]

{{Medical resources

| DiseasesDB = 29816

| ICD10 = {{ICD10|E|72|3|e|70}}

| ICD9 = {{ICD9|277.85}}

| ICDO =

| OMIM = 231680

| MedlinePlus =

| eMedicineSubj =

| eMedicineTopic =

| MeshID = D054069

|Orphanet=26791|ICD11={{ICD11|5C52.01}}|GARDNum=6523|GARDName=multiple-acyl-coa-dehydrogenase-deficiency|NORD=glutaricaciduria-ii}}

{{Amino acid metabolic pathology}}

{{Fatty-acid metabolism disorders}}

Category:Amino acid metabolism disorders

Category:Autosomal recessive disorders

Category:Rare diseases