General Condition Information
There are no other recognized names for this condition.
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- It is unknown how many babies are born with this rare condition each year in the United States.
- Visit GeneReviews to learn more about how often this condition occurs.
What is Ethylmalonic Encephalopathy
Ethylmalonic encephalopathy is an inherited (genetic) condition that prevents the body from breaking down a substance called sulfide. Sulfide is important for a number of functions in the body.
Babies who do not have enough ETHE1 enzyme cannot break down sulfide. When sulfide builds up, it becomes toxic, gets in the way of making energy, and damages organs throughout the body.
Without treatment, high levels of sulfide can damage the brain, muscles, blood vessels, and intestines. This damage leads to the signs and symptoms of the condition.
Newborn Screening and Follow-Up
Newborn screening for ethylmalonic encephalopathy requires collecting a small amount of blood from your baby’s heel. To learn more about this process, visit the Blood Spot Screening page.
Screening measures how much of certain substances (called acylcarnitines) are in your baby’s blood. Babies with high levels of these substances might have ethylmalonic encephalopathy.
If your baby’s blood spot screening result for ethylmalonic encephalopathy is out-of-range, your baby’s health care provider will contact you. Together, you will discuss next steps and follow-up plans.
An out-of-range screening result does not mean that your baby definitely has the condition. It does mean that your baby needs more follow-up testing. To learn more about screening results, visit the Blood Spot Screening Results page.
Your baby may need the following tests after an out-of-range screening result:
- Blood and/or urine tests
- Genetic testing using a blood sample
You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems right away if they are not diagnosed and treated quickly.
False-positive newborn screening results for this condition can happen. Babies given carnitine might receive false-positive results. Babies with other conditions with high levels of C4 acylcarnitine may also be detected through this screening. Examples of other conditions that may be detected are short-chain acyl-CoA dehydrogenase deficiency and isobutyryl-CoA dehydrogenase deficiency.
Newborn screening helps babies lead healthier lives. If your baby has an out-of-range result, follow up with your health care provider quickly. It is important to follow their instructions. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps.
Signs of ethylmalonic encephalopathy often appear shortly after birth (within a few days). In some cases, signs might not appear until a month or two after birth.
Signs of the condition may include the following:
- Weak muscles (hypotonia)
- Red rash
- Developmental delay
- Blue-ish hands and feet
- Chronic diarrhea
The condition is caused by a change in the ETHE1 gene. This gene gives your body instructions for making the ETHE1 enzyme that breaks down sulfide.
Without a working copy of the ETHE1 gene, your baby cannot produce enough ETHE1 enzyme and properly break down sulfide or make energy.
- Ethylmalonic encephalopathy is an autosomal recessive condition. Babies inherit the condition when each parent passes down a nonworking ETHE1 gene to their baby. Only babies with two nonworking ETHE1 genes—one from the mom and one from the dad—have this condition.
- People with one working copy and one nonworking copy of the ETHE1 gene are called carriers.
- Carriers do not have or develop the condition. However, they may pass down a nonworking copy of the gene to their children.
- If two parents are carriers of a nonworking copy of the ETHE1 gene, they have a 1 in 4 chance of having a child with ethylmalonic encephalopathy.
- Carriers for ethylmalonic encephalopathy often do not know they are carriers before having a child with the condition. In most cases, families have no history of the condition until the birth of a child with ethylmalonic encephalopathy.
- Parents who already have a child with ethylmalonic encephalopathy still have a 1 in 4 chance of having another child with ethylmalonic encephalopathy. This 1 in 4 chance stays the same for all future children.
- Genetic counselors and medical geneticists can help families learn about this condition and the chance of having children with it. Visit the National Society of Genetic Counselors to find a genetic counselor and the American College of Medical Genetics and Genomics to find a medical geneticist.
Treatment and Management
It is important to talk to your health care provider about which treatment(s) are best for your baby. While there are no treatment options available that can stop the progression of ethylmalonic encephalopathy, there are treatments to help with some of the symptoms.
Treatments may include the following:
- Muscle relaxants
- Physical therapy
- Medications to help seizures