Conditions Ethylmalonic Encephalopathy
Ethylmalonic encephalopathy (EME) is an inherited condition that affects many systems of the body. Children with EME usually develop severe problems with the nervous system, developmental delays, chronic diarrhea, and cardiovascular problems. For some individuals with EME, detecting it early and beginning treatment may help delay some of the serious health outcomes associated with the condition.
Organic Acid Conditions
How common is ethylmalonic encephalopathy?
Ethylmalonic encephalopathy (EME) is a very rare condition that has only been documented in 30 individuals worldwide. EME appears to occur more often in Arab and Mediterranean populations.
Also known as
- Encephalopathy, petechiae, and ethylmalonic aciduria
- EPEMA syndrome
- Ethylmalonic acidemia
Your baby’s doctor may ask you if your baby is showing any of the signs of ethylmalonic encephalopathy (see Early Signs below). If you baby has certain signs, your baby’s doctor may suggest starting immediate treatment.
If your baby’s newborn screening result for ethylmalonic encephalopathy (EME) was out of the normal range, your baby’s doctor or the state screening program will contact you to arrange for your child to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. An out-of-range result may occur because the initial blood sample was too small or the test was performed too early. However, as a few babies do have the condition, it is very important that you go to your follow-up appointment for a confirmatory test. Because the harmful effects of untreated EME can occur soon after birth, follow-up testing must be completed as soon as possible to determine whether or not your baby has the condition.
Follow-up testing will involve checking your baby’s blood and urine samples for signs of EME. Harmful amounts of certain substances build up in the body when a child has an inborn error of metabolism, so measuring the amounts of these substances in your baby’s body can help doctors determine if your baby has a condition. High amounts of ethylmalonic acid and lactic acid in the urine and high amounts of C4 and C5 acylcarnitine in the blood might indicate that your baby has EME. However, the condition can only be confirmed by looking for a specific change in your baby’s genes.
About Ethylmalonic Encephalopathy
Signs of ethylmalonic encephalopathy (EME) can begin any time during infancy. Usually, signs are evident at birth or begin in the first few months of life. Signs of EME include:
- Progressively delayed development
- Weak muscle tone (hypotonia)
- Abnormal movements
- Rashes of tiny red spots (petechiae)
- Blue discoloration in hands and feet (acrocyanosis)
- Chronic diarrhea
If your baby shows any of these signs, be sure to contact your baby’s health care provider immediately.
Your baby may need to be on a restricted diet in order to avoid the foods that his or her body cannot break down. A dietician or a nutritionist can help you plan a healthy diet for your child (see Accessing Care).
Supplements and Medications
Your baby’s health care provider may recommend L-carnitine, riboflavin, Q10s, and/or other vitamin supplements, which may help your baby produce energy and reduce damage to cells and tissues caused by a build-up of toxic substances.
Because the processes responsible for EME are not well understood, more effective treatments have not yet been developed.
If ethylmalonic encephalopathy (EME) is diagnosed early, treatment can slow some of the signs mentioned in the Early Signs section. This is why newborn screening is so important.
Although milder, chronic forms of this condition have been reported, most individuals with EME will pass away in childhood.
Mitochondria are the energy-making factories of the cell. They contain enzymes that help produce energy so cells can function. In individuals with ethylmalonic encephalopathy (EME), the mitochontrial enzyme, ETHE1, is not working properly.
If your baby has EME, his or her body is missing or making non-working copies of ETHE1 enzyme. When this enzyme is not working correctly, your baby’s mitochondria cannot make enough energy. The loss of this enzyme can also cause ethylmalonic acid, lactic acid, and other toxic substances to build up in cells throughout your baby’s body.
Little is known about how non-working ETHE1 enzymes cause the progressive nervous system problems of EME. Researchers suggest that the build-up of toxic substances in the brain and changes in blood flow to the brain may cause the nervous system damage characterized by EME.
EME is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for EME, one from each parent, in order to have the condition. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition. While having a child with EME is rare, when both parents are carriers, they can have more than one child with the condition. Learn more about autosomal recessive inheritance.
Support for Ethylmalonic Encephalopathy
Support groups can help connect families who have a child or other family member affected with ethylmalonic encephalopathy (EME) with a supportive community of people who have experience and expertise in living with the condition. These organizations offer resources for families, affected individuals, health care providers, and advocates.
Work with your baby’s health care provider to determine the next steps for your baby’s care. Your baby’s doctor may help you coordinate care with a physician that specializes in metabolism, a neurologist, a dietician who can help plan your child’s specialized diet, and other medical resources in your community. Some children with ethylmalonic encephalopathy (EME) have developmental delays. If you think that your baby is not meeting his or her developmental milestones, ask your baby’s doctor about the next steps in accessing a developmental evaluation and care.
Because EME is a genetic condition, you may want to talk with a genetics specialist. A genetic counselor or geneticist can help you understand the causes of the condition, discuss genetic testing for EME, and understand what this diagnosis means for other family members and future pregnancies. Speak with your baby’s doctor about getting a referral. The Clinic Services Search Engine offered by the American College of Medical Genetics and Genomics (ACMG) and the Find a Genetic Counselor tool on the National Society of Genetic Counselors (NSGC) website are two good resources for you or your baby's health care provider to use to identify local specialists.
References & Sources
Visit Genetics Home Reference from the National Library of Medicine for more condition information
Visit OrphaNet for more information on ethylmalonic encephalopathy
Visit OMIM to search its online catalog of human genes and disorders