Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment and Outcomes
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment and Outcomes
Medium chainacyl-coenzyme A dehydrogenasedeficiency (MCAD deficiency) is a rare and potentially serious inherited condition that affects the body’s ability to convert a certain fat into energy. Symptoms like vomiting and trouble breathing can develop soon after birth and turn deadly if left untreated.
Today, testing for MCAD deficiency is part of standardnewborn screeningsin the United States. When diagnosed promptly, MCAD deficiency can be treated and the child can expect to live a normal life expectancy.
This article describes the symptoms and causes of MCAD deficiency, including how the genetic disorder is passed from parents to children. It also explains how MCAD deficiency is diagnosed and treated along with the risk of death from the rare genetic disorder.
What Are the Signs and Symptoms of MCAD Deficiency?
People with MCAD deficiency have a genetic mutation that prevents the conversion of a certain type of fat—medium-chainfatty acids—into energy.The body typically relies on these fats during periods of fasting or whenever the body is under stress, such as during an illness.
Symptoms of MCAD deficiency usually start early in life and generally appear soon after a child has gone for a long stretch without eating. With prolonged fasting, children with MCAD deficiency experience suddenhypoglycemia(low blood sugar) and liver dysfunction.
In newborns, symptoms may be kept at bay while on regular feeding schedules. However, once there are longer stretches between feedings, the symptoms may become more and more apparent.
Symptoms of MCAD deficiency typically start between the ages of 1 month and 2 years and many include:
MCAD Deficiency and Sudden DeathAccording to the National Organization for Rare Disorders, MCAD deficiency is a known cause ofsudden infant death syndrome (SIDS).
MCAD Deficiency and Sudden Death
According to the National Organization for Rare Disorders, MCAD deficiency is a known cause ofsudden infant death syndrome (SIDS).
When not fasting or ill, people with MCAD deficiency usually do not have any symptoms.
What Causes MCAD Deficiency?
The gene mutation is passed in anautosomal recessive pattern. What this means is that both parents must be carriers of the ACADM gene mutation for the child to inherit and develop the disorder.
If only one parent has the gene mutation, then the child will inherit only one gene and also become a carrier without any symptoms. They, in turn, will be able to pass the gene to their child if they ever conceive.
There are several mutations of the ACADM gene that could lead to MCAD deficiency, which may explain why some children have worse symptoms than others. In some cases, a person may only experience symptoms during adulthood.
Is MCAD Deficiency Common?MCAD deficiency is rare, affecting roughly one of every 17,000 newborns. White people of northern European ancestry are at highest risk. Males and females are equally affected.
Is MCAD Deficiency Common?
MCAD deficiency is rare, affecting roughly one of every 17,000 newborns. White people of northern European ancestry are at highest risk. Males and females are equally affected.
How Is MCAD Deficiency Diagnosed?
The U.S. Department of Health and Human Services recommends MCAD deficiency testing as part of routine newborn screening. The primary benefit of screening is that an infant can be diagnosed before symptoms develop.
If the screening indicates MCAD deficiency, additional testing can provide more information. The parents and siblings would also undergo genetic testing.
Other tests used to confirm a diagnosis of MCAD deficiency include:
If a person doesn’t experience symptoms until adulthood, MCAD deficiency may not be at the top of the list of medical causes. It may only be after all other causes are excluded that MCAD deficiency is considered and genetic testing is performed.
How Do You Treat MCAD Deficiency?
The primary way to treat MCAD deficiency is to avoid prolonged fasting and ensure proper nutrition. Parents will be given strict instructions about feeding to prevent any long periods of fasting.
In addition to having regular bottle feedings, some specialists recommend that infants be given a special formula with added simple carbohydrates (sugars, such as uncooked cornstarch) to help prevent drops in blood sugar.
Children and adults with MCAD deficiency would also be advised to adhere to a specific diet that includes higher amounts of carbohydrates and lower amounts of fat than would typically be recommended for their age group.
In addition to ensuring appropriate nutrition, strict adherence to a regular feeding schedule will need to begin from the time of diagnosis.
Feeding Schedules for MCAD DeficiencyExperts recommend the following maximum fasting times for people with MCAD deficiency:Infants should be fed every two to three hours.Babies between 6 months and 12 months should go no longer than eight hours without eating,Children 12 months to 24 years should go no longer than 10 hours without eating,Children and adults over age 2 should not go longer than 12 hours without eating.
Feeding Schedules for MCAD Deficiency
Experts recommend the following maximum fasting times for people with MCAD deficiency:Infants should be fed every two to three hours.Babies between 6 months and 12 months should go no longer than eight hours without eating,Children 12 months to 24 years should go no longer than 10 hours without eating,Children and adults over age 2 should not go longer than 12 hours without eating.
Experts recommend the following maximum fasting times for people with MCAD deficiency:
If a person with MCAD deficiency becomes ill and cannot eat, they may need to receive nutrition and fluids through an IV drip or feeding tube at the hospital to prevent complications.
What is the life expectancy of someone with MCAD deficiency?If MCAD deficiency is properly managed, a person can live a long and healthy life. However, if left undiagnosed and untreated, the risk of death is estimated to be around 20%. Most deaths occur during early childhood.
What is the life expectancy of someone with MCAD deficiency?
If MCAD deficiency is properly managed, a person can live a long and healthy life. However, if left undiagnosed and untreated, the risk of death is estimated to be around 20%. Most deaths occur during early childhood.
Summary
MCAD deficiency is a rare genetic condition that affects the body’s ability to convert certain fats into energy. The deficiency occurs when two parents with a specific gene mutation pass it to their child. If the condition goes undiagnosed and untreated, it can be fatal.
People with MCAD deficiency usually need to adhere to a diet that is high in carbohydrates and low in fat. They also need to avoid long periods of fasting. If properly managed, most people with MCAD deficiency can lead normal, healthy lives.
6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Organization for Rare Disorders.Medium chain acyl coA dehydrogenase deficiency.Vandenberghe C, St-Pierre V, Fortier M, et al.Medium chain triglycerides modulate the ketogenic effect of a metabolic switch.Front Nutr. 2020;7(3). doi:10.3389/fnut.2020.00003Lovera C, Porta F, Caciotti A, et al.Sudden unexpected infant death (SUDI) in a newborn due to medium chain acyl CoA dehydrogenase (MCAD) deficiency with an unusual severe genotype.Ital J Pediatr. 2012;38:59. doi:10.1186/1824-7288-38-59MedlinePlus.Medium-chain acyl-CoA dehydrogenase deficiency. Aug 18, 2020.Merritt JL, Change IJ.Medium-chain acyl-coenzyme a dehydrogenase deficiency. GeneReviews [Internet]. June 27, 2019.Gartner V, McGuire PJ, Lee PR.Child neurology: medium-chain acyl-coenzyme A dehydrogenase deficiency,Neurology.2015 Jul 28;85(4):e37–e40. doi:10.1212/WNL.0000000000001786
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Organization for Rare Disorders.Medium chain acyl coA dehydrogenase deficiency.Vandenberghe C, St-Pierre V, Fortier M, et al.Medium chain triglycerides modulate the ketogenic effect of a metabolic switch.Front Nutr. 2020;7(3). doi:10.3389/fnut.2020.00003Lovera C, Porta F, Caciotti A, et al.Sudden unexpected infant death (SUDI) in a newborn due to medium chain acyl CoA dehydrogenase (MCAD) deficiency with an unusual severe genotype.Ital J Pediatr. 2012;38:59. doi:10.1186/1824-7288-38-59MedlinePlus.Medium-chain acyl-CoA dehydrogenase deficiency. Aug 18, 2020.Merritt JL, Change IJ.Medium-chain acyl-coenzyme a dehydrogenase deficiency. GeneReviews [Internet]. June 27, 2019.Gartner V, McGuire PJ, Lee PR.Child neurology: medium-chain acyl-coenzyme A dehydrogenase deficiency,Neurology.2015 Jul 28;85(4):e37–e40. doi:10.1212/WNL.0000000000001786
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Organization for Rare Disorders.Medium chain acyl coA dehydrogenase deficiency.Vandenberghe C, St-Pierre V, Fortier M, et al.Medium chain triglycerides modulate the ketogenic effect of a metabolic switch.Front Nutr. 2020;7(3). doi:10.3389/fnut.2020.00003Lovera C, Porta F, Caciotti A, et al.Sudden unexpected infant death (SUDI) in a newborn due to medium chain acyl CoA dehydrogenase (MCAD) deficiency with an unusual severe genotype.Ital J Pediatr. 2012;38:59. doi:10.1186/1824-7288-38-59MedlinePlus.Medium-chain acyl-CoA dehydrogenase deficiency. Aug 18, 2020.Merritt JL, Change IJ.Medium-chain acyl-coenzyme a dehydrogenase deficiency. GeneReviews [Internet]. June 27, 2019.Gartner V, McGuire PJ, Lee PR.Child neurology: medium-chain acyl-coenzyme A dehydrogenase deficiency,Neurology.2015 Jul 28;85(4):e37–e40. doi:10.1212/WNL.0000000000001786
National Organization for Rare Disorders.Medium chain acyl coA dehydrogenase deficiency.
Vandenberghe C, St-Pierre V, Fortier M, et al.Medium chain triglycerides modulate the ketogenic effect of a metabolic switch.Front Nutr. 2020;7(3). doi:10.3389/fnut.2020.00003
Lovera C, Porta F, Caciotti A, et al.Sudden unexpected infant death (SUDI) in a newborn due to medium chain acyl CoA dehydrogenase (MCAD) deficiency with an unusual severe genotype.Ital J Pediatr. 2012;38:59. doi:10.1186/1824-7288-38-59
MedlinePlus.Medium-chain acyl-CoA dehydrogenase deficiency. Aug 18, 2020.
Merritt JL, Change IJ.Medium-chain acyl-coenzyme a dehydrogenase deficiency. GeneReviews [Internet]. June 27, 2019.
Gartner V, McGuire PJ, Lee PR.Child neurology: medium-chain acyl-coenzyme A dehydrogenase deficiency,Neurology.2015 Jul 28;85(4):e37–e40. doi:10.1212/WNL.0000000000001786
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