Acyl-coa dehydrogenase, short-chain, deficiency of
Overview
What is Short chain acyl-CoA dehydrogenase deficiency (SCADD)?
Short chain acyl-CoA dehydrogenase deficiency, or SCADD, is a genetic disease in which the body is not able to properly break down fat to create energy. SCADD is one of a group of disorders called fatty acid oxidation disorders. The body usually gets its energy by breaking down (sometimes called "burning") sugars and fats. People with SCADD are able to break down sugar normally but, because of a problem in the gene called ACADS they are not able to break down a type of fat called short chain fatty acids.
Most people who have SCADD do not have any symptoms. At this time (2016), researchers do not understand why some people with SCADD have symptoms and others do not. For people with SCADD who do have symptoms, these symptoms include problems eating, low muscle tone (they may be floppy), delays in development, vomiting, low energy (lethargy) and seizures in infants and muscle cramps or pain and difficulty with exercise or episodes of nausea, vomiting and shortness of breath in older children and adults.
When a person with SCADD is healthy and eating regularly, they are able to get enough energy from the sugars in their diet and they appear totally healthy. However, when certain people with SCADD go a long time without eating and their bodies begin to burn fat for energy, they can become sick with a metabolic crisis, which can cause excessive sleepiness or irritability, vomiting or diarrhea, and increased levels of acids in the blood (metabolic acidosis). If a metabolic crisis is not treated, the child may have seizures, problems breathing, or coma. Common reasons for going without food include illness, operations, or when babies begin to sleep through the night.
References
- New England Consortium of Metabolic Programs. (2010). SCADD: A Guide for Parents of Babies Recently Screened for SCADD. Retrieved from New England Consortium of Metabolic Programs: http://newenglandconsortium.org/for-families/other-metabolic-disorders/fatty-acid-oxidation-disorders/scadd/
- Wolfe L, Jethva R, Oglesbee D, et al. Short-Chain Acyl-CoA Dehydrogenase Deficiency. 2011 Sep 22 [Updated 2014 Aug 7]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016.http://www.ncbi.nlm.nih.gov/books/NBK63582/
- Longo, N. (2011). Short-chain acyl-CoA deficiency (SCADD). https://www.medicalhomeportal.org/newborn/short-chain-acyl-coa-deficiency
- Screening, Technology And Research in Genetics (STAR-G). (2016). Genetic Fact Sheets for Parents: SCADD. http://www.newbornscreening.info/Parents/fattyaciddisorders/SCADD.html
More Overview Content
Are there other names for Short chain acyl-CoA dehydrogenase deficiency (SCADD)?
How common is Short chain acyl-CoA dehydrogenase deficiency (SCADD)?
Are there different forms of Short chain acyl-CoA dehydrogenase deficiency (SCADD)?
Are there other names for Short chain acyl-CoA dehydrogenase deficiency (SCADD)?
Other names for Short-Chain Acyl-Coenzyme A Dehydrogenase Deficiency include:
- SCADD, (pronounced S-cad)
- SCAD deficiency, (pronounced S-cad deficiency)
- Short-chain acyl-CoA deficiency
- Short chain acyl-CoA dehydrogenase deficiency
- Acyl-CoA dehydrogenase short chain (ACADS) deficiency
- Deficiency of butyryl-CoA dehydrogenase
SCADD belongs to a category of diseases called "Fatty Acid Oxidation Disorders" in which the body is not able to properly break down fats for energy.
References
- Longo, N. (2011). Short-chain acyl-CoA deficiency (SCADD).https://www.medicalhomeportal.org/newborn/short-chain-acyl-coa-deficiency
- http://www.omim.org/entry/201470
How common is Short chain acyl-CoA dehydrogenase deficiency (SCADD)?
The genetic mutations that cause SCADD are estimated to occur in between 1 in 35,000 to 1 in 85,000 people.
Most people diagnosed with SCADD never develop symptoms.
References
- Longo, N. (2011). Short-chain acyl-CoA deficiency (SCADD) https://www.medicalhomeportal.org/newborn/short-chain-acyl-coa-deficiency
- Wolfe L, Jethva R, Oglesbee D, et al. Short-Chain Acyl-CoA Dehydrogenase Deficiency. 2011 Sep 22 [Updated 2014 Aug 7]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016. http://www.ncbi.nlm.nih.gov/books/NBK63582/
Are there different forms of Short chain acyl-CoA dehydrogenase deficiency (SCADD)?
SCADD affects people differently. Most children and adults with SCADD never have any symptoms.
Others have very mild symptoms or only develop symptoms when they have another condition that puts extra stress on their bodies.
Some infants and children with SCADD have serious symptoms such as growth and developmental delays, low blood sugar, and seizures.
Another form of SCADD is only found in adults. The adult form of SCADD mainly affects the muscles. It can cause muscle pain and weakness. Adults with SCADD may also have nausea, vomiting, and shortness of breath. The muscle problems often get worse after strenuous exercise.
Everyone with SCADD has mutations (changes) in the same gene. The gene is called ACADS. This gene provides the instructions for making the enzyme, or protein, called "short acyl-coenzyme A dehydrogenase," or "SCAD" which breaks down fat for energy. Different mutations in the gene cause different problems in the enzyme. Some mutations stop the enzyme from working at all and others just slow it down. The different types of SCADD can by partially explained by the different types of mutations since people with mutations that just slow the enzyme down are still able to break down some short chain fats while people with mutations that stop the enzyme from working at all are not able to to break down any. But there seem to be other factors, perhaps other genes or other illnesses, that also affect whether a person with SCADD will show symptoms. Researchers are working to understand these differences better.
References
- STAR-G. (2016). Genetic Fact Sheet for Parents: Fatty Acid Oxidation Disorders: Short Chain Acyl-CoA Dehydrogenase Deficiency http://www.newbornscreening.info/Parents/fattyaciddisorders/SCADD.html#3
- Wolfe L, Jethva R, Oglesbee D, et al. Short-Chain Acyl-CoA Dehydrogenase Deficiency. 2011 Sep 22 [Updated 2014 Aug 7]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016. http://www.ncbi.nlm.nih.gov/books/NBK63582/
- Longo, N. (2011). Short-chain acyl-CoA deficiency (SCADD). https://www.medicalhomeportal.org/newborn/short-chain-acyl-coa-deficiency
