General Condition Information
- 3-hydroxyacyl-coenzyme A dehydrogenase deficiency, previously named Medium/short-chain L-3-hydroxyacl-CoA dehydrogenase
- Medium/short chain 3 hydroxyacyl CoA dehydrogenase deficiency
- Medium/short chain hydroxyacl CoA dehydrogenase deficiency
- Medium/short chain L-3-hydroxyacyl-CoA dehydrogenase deficiency
- Medium/short-chain 3-hydroxyacyl-CoA dehydrogenase deficiency
- Medium/short-chain 3-OH acyl-CoA dehydrogenase deficiency
- Medium/short-chain hydroxy acyl-CoA dehydrogenase deficiency
- Medium/short-chain L-3-hydroxy ACYL-CoA dehydrogenase deficiency
- Medium/short-chain L-3-hydroxy acyl-CoA dehydrogenase deficiency
- Medium/short-chain L-3-hydroxyacyl-CoA dehydrogenase deficiency
- Medium/short-chain L-3-hydroxyaxl-CoA dehydrogenase deficiency
- Medium/short-chain L-3-OH acyl-CoA dehydrogenase deficiency
- SCHAD deficiency
- Short chain 3-hydroxyacyl-CoA dehydrogenase deficiency
The number of babies born with this very rare condition is currently unknown.
What is 3-hydroxyacyl-CoA dehydrogenase deficiency
3-Hydroxyacyl-CoA dehydrogenase is an enzyme in your body that processes types of fat called short-chain fatty acids and medium-chain fatty acids. This enzyme helps break down these fatty acids so your body can use them or get rid of them.
Without enough working 3-hydroxyacyl-CoA dehydrogenase enzyme, the body has trouble using fats for energy. This condition can be more or less severe depending on how many normal copies of the enzyme your baby can make.
Breaking down fat for energy allows your body to work properly, and it is especially important after a long time without food (fasting) and during illness. If your body does not make enough energy from fat, blood sugar levels can become dangerously low.
When fats are not processed, waste (including toxins) can build up and damage your liver, heart, and muscles. Insulin, a protein that helps keep blood sugar at a normal level, also builds up.
Newborn Screening and Follow-Up
Newborn screening for 3-hydroxyacyl-CoA dehydrogenase deficiency is done using a small amount of blood collected from your baby’s heel. To learn more about this process, visit the Blood Spot Screening page.
During screening, a special machine measures how much of certain substances (called acylcarnitines) are in your baby’s blood. Your body produces these substances when it makes energy from fats. Babies with high levels of these substances might have 3-hydroxyacyl-CoA dehydrogenase deficiency.
If your baby’s blood spot screening result for 3-hydroxyacyl-CoA dehydrogenase deficiency 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 test
- Genetic testing using a blood sample
- Small skin sample
You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems if they are not diagnosed and treated quickly.
False-positive newborn screening results for this condition do not happen often. Because this condition is very rare, it is not known what can lead to false-positive results, or how often they occur.
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. Your baby may need to get treatment right away, even if they are not showing signs or symptoms. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps. Careful monitoring and early treatment will help your baby stay as healthy as possible.
Signs of 3-hydroxyacyl-CoA dehydrogenase deficiency often appear shortly after birth (1 month to 2 years of age). They can be triggered by common illnesses (like a cold or flu) or a long time without food.
Signs of the condition may include the following:
The condition is caused by a change in the HADH gene. This gene gives the body instructions for making 3-hydroxyacyl-CoA dehydrogenase. 3-hydroxyacyl-CoA dehydrogenase is an enzyme that helps breaks down certain types of fats called medium-chain fatty acids and short-chain fatty acids. These types of fats are important sources of energy for the heart, liver, and muscles.
Without a working HADH gene, your baby cannot make enough 3-hydroxyacyl-CoA dehydrogenase enzyme. As a result, their body cannot properly break down fat to make energy and get rid of toxins.
- 3-Hydroxyacyl-CoA dehydrogenase deficiency is an autosomal recessive condition. Babies inherit the condition when each parent passes down a nonworking HADH gene to their baby. Only babies with two nonworking HADH genes—one from the mom and one from the dad—have this condition.
- People with one working copy and one nonworking copy of the HADH 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 HADH gene, they have a 1 in 4 chance of having a child with 3-hydroxyacyl-CoA dehydrogenase deficiency.
- Carriers for 3-hydroxyacyl-CoA dehydrogenase deficiency 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 3-hydroxyacyl-CoA dehydrogenase deficiency.
- Parents who already have a child with 3-hydroxyacyl-CoA dehydrogenase deficiency still have a 1 in 4 chance of having another child with 3-hydroxyacyl-CoA dehydrogenase deficiency. 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. The goal of treatment is to prevent the health problems caused by this condition.
Treatments may include the following:
- Regular and frequent meals and snacks
- Diet high in carbohydrates and low in fat
- L-carnitine supplements to help the body break down fats
- Medications to help lower insulin to a normal level (in some cases)
Even with treatment, some children may still have high insulin levels, low blood sugar levels, or problems with their heart or liver.