MCAD is one of several Fatty Acid Oxidation Disorders (FAOD) in which there is an inability to break down certain fats. This is caused by an enzyme deficiency. This results in a decreased ability to go without food or calories for a long time (fasting).
About one in every 5-17,000 babies is born with MCAD. MCAD is most prevalent in Caucasians, especially those of Northern European descent, although it can occur in any racial or ethnic group.
MCAD can be detected through newborn screening. With treatment from infancy, children with MCAD are expected to live a full life. However, they are still at risk for complications in times of illness.
Prior to newborn screening, a previously healthy child with MCAD deficiency would present with hypoglycemia (low blood sugar), vomiting, and lethargy triggered by a common illness. If untreated, seizures could occur and such episodes could quickly progress to coma and death. Enlarged liver and acute liver disease may also be present. With newborn screening MCAD is usually diagnosed at birth in the United States. Children with MCAD do not have any distinct physical features. Although MCAD can not be seen, it is a serious condition. Good communication between parents, doctors, and school personnel is very important.
Note: There is wide variability within individuals who have this condition.
This information was last updated in May 2020.