Fatty-acid metabolism disorder

Fatty-acid metabolism disorder
Classification and external resources

Acyl-CoA, one of the compounds involved in fatty acid metabolism
ICD-10 E71.3
ICD-9 277.81-277.85

A broad classification for genetic disorders that result from an inability of the body to produce or utilize one enzyme that is required to oxidize fatty acids. The enzyme can be missing or improperly constructed resulting in it not working. This leaves the body unable to produce energy within the liver and muscles from fatty acid sources.[1]

The body's primary source of energy is glucose, however, when all the glucose in the body has be expended a normal body digests fats. Individuals with a Fatty acid metabolism disorder are unable to metabolize the fat source for energy halting bodily processes.[1] Most individuals with a Fatty-acid metabolism disorder are able to live a normal active live with simple adjustments to diet and medications.

If left undiagnosed many complications can arise. When in need of glucose the body of a person with a fatty-acid metabolism disorder will still send fats to the liver. The fats are broken down to fatty acids. The fatty acids are then transported to the target cells but are unable to be broken down resulting in a build up of fatty acids in the liver and other internal organs.

They are sometimes classified with the lipid metabolism disorders,[2] but in other contexts they are considered a distinct category.

Contents

Possible Symptoms

Diagnosis

Diagnosis of Fatty-acid metabolism disorder requires extensive lab testing. There are many labs that can be used for testing and diagnosing Fatty-acid metabolism disorders. Eg. http://genes-r-ushttp://genes-r-us.uthscsa.edu/parentpage.htm.uthscsa.edu/parentpage.htm

Normally, in cases of hypoglycaemia, triglycerides and fatty acids are metabolised to provide glucose/energy. However, in this process, ketones are also produced, thus usually ketotic hypoglycaemia is expected. However, in cases where fatty acid metabolism is impaired, a non-ketotic hypoglycaemia may be the result, due to a break in the metabolic pathways for fatty acid metabolism.

Causes

Fatty-acid metabolism disorders result when both parents of the diagnosed subject are carriers of the defective genes. This type of disorder is know as autosomal recessive disorder. Two parts of a recessive gene are required to activate the disease. If only one part of the gene is present then the individual is only a carrier and shows know symptoms of the disease. If both genes are present then the disease is activated. Like most autosomal recessive disorders, when both parents are carriers, there is a 25% chance of the child gaining the disease.[3]

Types

Incomplete list of various fatty-acid metabolism disorders.[1]

Oxidation

The term fatty acid oxidation disorder (FAOD) is sometimes used, especially when there is an emphasis on the oxidation of the fatty acid.[4]

In addition to the fetal complications, they can also cause complications for the mother during pregnancy.[5]

Examples include:

Carnitine/transport

The fatty acids are transported by carnitine, and defects in this process are associated with several disorders.[7] They involve the step immediately before oxidation, and are often grouped with the oxidation disorders.

Treatment

The primary treatment method for fatty-acid metabolism disorders is dietary modifications. It is essential that the blood-glucose levels remain at adequate levels to prevent the body from moving fat to the liver for energy. This involves snacking on low fat, high carbohydrate every 2-6 hours. Some adult and children can sleep through the night 8-10 hours without snacking.[1][3]

Drugs

Carnitor - an L-carnitine supplement that has show to improve the body's metabolism in individuals with low L-carnitine levels. It is only useful for Specific fatty-acid metabolism disease.[1]

See also

References

  1. ^ a b c d e f g h Gould D. (2011). List of FODs and symptoms. http://www.fodsupport.org/list.htm. 
  2. ^ "Lipid Metabolism: Hereditary Metabolic Disorders: Merck Manual Home Edition". http://www.merck.com/mmhe/sec23/ch282/ch282d.html. Retrieved 2009-03-11. 
  3. ^ a b c d e f g h i j k "Fatty Acid Oxidation Disorders". http://www.newbornscreening.info/Parents/fattyaciddisorders/CTD.pdf. Retrieved 2011-11-11. 
  4. ^ a b Shekhawat PS, Matern D, Strauss AW (May 2005). "Fetal fatty acid oxidation disorders, their effect on maternal health and neonatal outcome: impact of expanded newborn screening on their diagnosis and management". Pediatr. Res. 57 (5 Pt 2): 78R–86R. doi:10.1203/01.PDR.0000159631.63843.3E. PMID 15817498. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=0031-3998&volume=57&issue=5&spage=78R. 
  5. ^ Ibdah JA, Bennett MJ, Rinaldo P, et al (June 1999). "A fetal fatty-acid oxidation disorder as a cause of liver disease in pregnant women". N. Engl. J. Med. 340 (22): 1723–31. doi:10.1056/NEJM199906033402204. PMID 10352164. http://content.nejm.org/cgi/pmidlookup?view=short&pmid=10352164&promo=ONFLNS19. 
  6. ^ "Fatty Acid and Glycerol Metabolism Disorders: Inherited Disorders of Metabolism: Merck Manual Professional". http://www.merck.com/mmpe/sec19/ch296/ch296e.html. Retrieved 2009-03-11. 
  7. ^ Longo N, Amat di San Filippo C, Pasquali M (May 2006). "Disorders of carnitine transport and the carnitine cycle". Am J Med Genet C Semin Med Genet 142C (2): 77–85. doi:10.1002/ajmg.c.30087. PMC 2557099. PMID 16602102. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2557099.