General Condition Information
- Formiminoglutamic acidemia
- Formiminoglutamic acidemia, glutamate formiminotransferase deficiency
- It is unknown how many babies are born with this rare condition each year in the United States.
What is Glutamate Formiminotransferase Deficiency
Glutamate formiminotransferase deficiency is an inherited (genetic) condition that prevents the breakdown of histidine. Histidine is an amino acid, one of the building blocks that makes up proteins.
Without enough working FTCD enzyme, your baby will have trouble breaking down histidine and making folate. Most babies with glutamate formiminotransferase deficiency are well or have very few signs and symptoms.
Newborn Screening and Follow-Up
Glutamate formiminotransferase deficiency may be detected by newborn screening. Newborn screening 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. While looking at acylcarnitine levels, sometimes the substance formiminoglutamate (FIGLU) is also seen. FIGLU builds up when histidine cannot be completely broken down. Babies with high levels of FIGLU might have glutamate formiminotransferase deficiency.
If your baby’s blood spot screening result for glutamate formiminotransferase 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.
Signs and symptoms of glutamate formiminotransferase deficiency are not yet fully understood. Most babies and children with this condition will be well and have no signs or symptoms.
In rare cases, signs of the condition in children may include the following:
- Developmental delay
- Low levels of red blood cells (anemia)
The condition is caused by a change in the FTCD gene. This gene gives the body instructions for making the FTCD enzyme, which helps break down the amino acid histidine. Without a working FTCD gene, your baby’s body cannot make enough working FTCD enzyme. As a result, their body has trouble breaking down histidine and making folate.
- Glutamate formiminotransferase deficiency is an autosomal recessive condition. Babies inherit it when each parent passes down a nonworking FTCD gene to their baby. Only babies with two nonworking FTCD genes—one from the mom and one from the dad—have this condition.
- People with one working copy and one nonworking copy of the FTCD 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 FTCD gene, they have a 1 in 4 chance of having a child with glutamate formiminotransferase deficiency.
- Carriers for glutamate formiminotransferase 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 glutamate formiminotransferase deficiency.
- Parents who already have a child with glutamate formiminotransferase deficiency still have a 1 in 4 chance of having another child with glutamate formiminotransferase deficiency. This 1 in 4 chance stays the same for 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 glutamate formiminotransferase deficiency typically do not need any treatment.
If your baby does have signs and symptoms of glutamate formiminotransferase deficiency, it is important to talk to your health care provider about which treatment(s), if any, your baby needs.