Glutaric acidemia type I

Newborn screening for glutaric acidemia type I 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. The body makes these substances when it breaks down food. Babies with high levels of these substances might have glutaric acidemia type I.

If your baby’s blood spot screening result for glutaric acidemia type I 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
• Small skin sample

You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems soon after birth if they are not diagnosed and treated quickly.

False-positive newborn screening results for this condition are rare.

Babies who received carnitine can have false-positive screening results for glutaric acidemia type I. Moms can also have glutaric acidemia type I without knowing it. Babies whose moms have this condition may have false-positive screening results for glutaric acidemia type I.

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 glutaric acidemia type I can vary widely. Without treatment, they most often appear between 4 months and 2 years of age.

Signs of the condition may include the following:

• Poor appetite
• Sleeping longer or more often
• Large head (macrocephaly)
• Difficulty moving
• Twitches or spasms
• Floppy arms and legs (hypotonia)
• Delayed growth
• Developmental delays

The condition is caused by a change in the GCDH gene. This gene gives your body instructions for making glutaryl-CoA dehydrogenase. Glutaryl-CoA dehydrogenase is an enzyme that helps you digest parts of certain proteins called lysine, hydroxylysine, and tryptophan.

Without a working GCDH gene, your baby’s body cannot make an enzyme that works well enough to properly break down proteins that contain lysine, hydroxylysine, and tryptophan. As a result, harmful toxins can build up in their body.

Glutaric acidemia type I is a genetic condition. Babies inherit it from their biological (birth) parents. To learn more about genetic conditions, visit MedlinePlus Genetics.

• Glutaric acidemia type I is an autosomal recessive condition. Babies inherit the condition when each parent passes down a nonworking GCDH gene to their baby. Only babies with two nonworking GCDH genes—one from the mom and one from the dad—have this condition.
  • People with one working copy and one nonworking copy of the GCDH 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 GCDH gene, they have a 1 in 4 chance of having a child with glutaric acidemia type I.
  • Carriers for glutaric acidemia type I 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 glutaric acidemia type I.
  • Parents who already have a child with glutaric acidemia type I still have a 1 in 4 chance of having another child with glutaric acidemia type I. 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.