General Condition Information
- SCAD deficiency
- Short chain acyl-CoA dehydrogenase deficiency
- Short chain acylCoA dehydrogenase deficiency
- Short-chain acyl CoA dehydrogenase deficiency
- Short-chain ACYL-COA dehydrogenase deficiency
- Each year, over 100 babies in the United States are born with short-chain acyl-CoA dehydrogenase deficiency.
- Visit GeneReviews to learn more about how often this condition occurs.
What is Short-chain acyl-CoA dehydrogenase deficiency
SCAD is an enzyme that processes types of fat called short-chain fatty acids so your body can use or get rid of them.
Babies who do not have enough of this enzyme may have trouble using fats for energy. 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.
Typically, babies with SCAD deficiency have very few signs and symptoms. In fact, most health care providers consider SCAD deficiency to be just a change in the body and not a condition.
Newborn Screening and Follow-Up
Newborn screening for SCAD 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. Babies with high levels of these substances might have SCAD deficiency.
If your baby’s blood spot screening result for SCAD 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 tests
- Genetic testing using a blood sample
You should complete any recommended follow-up testing as soon as possible.
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.
Most babies and children with SCAD deficiency have no signs or symptoms. In rare cases, some signs of the condition may be triggered by common illnesses (like a cold or flu) or a long time without food.
For children who do have signs of SCAD deficiency, signs may include the following:
- Low blood sugar (hypoglycemia)
- Small head size (microcephaly)
- Tiredness or lack of energy (lethargy)
The condition is caused by a change in the ACADS gene. This gene gives your body instructions for making short-chain acyl-CoA dehydrogenase (SCAD). SCAD is an enzyme that breaks down a certain type of fat called short-chain fatty acids.
Without a working copy of the ACADS gene, your baby’s body cannot produce enough SCAD enzyme and properly break down fat to make energy.
- SCAD deficiency is an autosomal recessive condition. Babies inherit the condition when each parent passes down a nonworking ACADS gene to their baby. Only babies with two nonworking ACADS genes—one from the mom and one from the dad—have this condition.
- People with one working copy and one nonworking copy of the ACADS 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 ACADS gene, they have a 1 in 4 chance of having a child with SCAD deficiency.
- Carriers for SCAD 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 SCAD deficiency.
- Parents who already have a child with SCAD deficiency still have a 1 in 4 chance of having another child with SCAD 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
Babies and children with SCAD deficiency typically do not need any treatment. If your baby does have signs and symptoms of SCAD deficiency, it is important to talk to your health care provider about which treatment(s), if any, your baby needs.