Conditions Formiminoglutamic Acidemia
Formiminoglutamic acidemia (FIGLU) is an inherited condition in which the body is unable to break down and process certain building blocks of protein, called amino acids. Individuals with FIGLU are also unable to produce a specific form of the vitamin folate, which has many important functions in the body. There are two forms of FIGLU which are classified in terms of severity. Both are associated with varying degrees of physical and mental disability.
How common is formiminoglutamic acidemia?
Formiminoglutamic acidemia (FIGLU) is a very rare genetic condition with only 20 identified cases, worldwide. About 25% of these individuals have the severe form of FIGLU and 75% have the mild form. All individuals with the severe form are of Japanese origin. Those with the mild form come from a variety of different backgrounds.
Also known as
- Arakawa syndrome 1
- Formiminoglutamic aciduria
- Formiminotransferase deficiency
- Glutamate formiminotransferase deficiency
Your baby’s doctor may ask you if your baby is showing any of the signs of formiminoglutamic acidemia (see Early Signs below).
If your baby’s newborn screening result for formiminoglutamic acidemia (FIGLU) was out of the normal range, your baby’s doctor or the state screening program will contact you to arrange for your child to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. An out-of-range result may occur because the initial blood sample was too small or the test was performed too early. However, as a few babies do have the condition, it is very important that you go to your follow-up appointment for a confirmatory test.
Follow-up testing will involve checking your baby’s urine and blood samples for signs of FIGLU. When a child has FIGLU, harmful amounts of certain substances build up in the body. Measuring the amounts of these substances in your baby’s body can help doctors determine if your baby has the condition. High levels of folates in the blood and/or high levels of a molecule called formiminoglutamate in the urine might indicate that your baby has FIGLU.
About Formiminoglutamic Acidemia
There are two forms of formiminoglutamic acidemia (FIGLU), which vary with regards to disease severity and symptoms. The mild form of FIGLU is associated with
- Mild developmental delay
- Mild intellectual disability
Signs of the severe form of FIGLU include:
- Severe intellectual disability
- Delayed development of motor skills such as sitting, standing and walking
- Decreased appetite
- Lack of energy
- Pale skin
- Tingling or numbness in hands and feet
If your baby shows any of these signs, be sure to contact your baby’s health care provider immediately.
There are currently no treatments available to prevent or delay the signs and symptoms of formiminoglutamic acidemia (FIGLU).
The outcome of formiminoglutamic acidemia (FIGLU) depends whether a baby has the mild or severe form of the condition. Individuals with mild FIGLU have minor delays in mental and physical development. Severe FIGLU is associated with profound mental disabilities and developmental delay. It is unclear why some individuals are affected more severely than others.
When we eat food, enzymes help break it down. Some enzymes help break down proteins into their building blocks, called amino acids. Other enzymes break down these amino acids into smaller components that can be used by the body. One specific enzyme known as formiminotransferase cyclodeaminase (FTCD) helps the body break down and process the amino acid, histidine. FTCD also helps produce a specific form of the vitamin folate, which has many important functions in the body.
If your baby has formiminoglutamic acidemia (FIGLU), his or her body is missing or making non-working copies of the enzyme FTCD. Without proper function of these enzymes, your baby’s body cannot break down histidine or produce certain forms of folate. However, it is unclear how these changes result in the health problems associated with FIGLU.
Formiminoglutamic acidemia (FIGLU) is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene, one from each parent, in order to have the condition. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition. While having a child with FIGLU is rare, when both parents are carriers, they can have more than one child with the condition. Learn more about autosomal recessive inheritance.
Support for Formiminoglutamic Acidemia
Support groups can help connect families who have a child or other family member affected with formiminoglutamic acidemia (FIGLU), with a supportive community of people who have experience and expertise in living with the condition or with similar metabolic disorders. These organizations offer resources for families, affected individuals, health care providers, and advocates.
Work with your baby’s health care provider to determine the next steps for your baby’s care. Most children with formiminoglutamic acidemia (FIGLU) have developmental delays. If you think that your baby is not meeting his or her developmental milestones, ask your baby’s doctor about the next steps in accessing a developmental evaluation and care.
Because FIGLU is a genetic condition, you may want to talk with a genetics specialist. A genetic counselor or geneticist can help you understand the causes of the condition, discuss genetic testing for FIGLU, and understand what this diagnosis means for other family members and future pregnancies. Speak with your baby’s doctor about getting a referral. The Clinic Services Search Engine offered by the National Coordinating Center for the Regional Genetic and Newborn Screening Service Collaboratives and the Find a Genetic Counselor tool on the National Society of Genetic Counselors (NSGC) website are two good resources for you or your baby's health care provider to use to identify local specialists.
References & Sources
Visit Genetics Home Reference from the National Library of Medicine for more condition information
Visit OMIM to search its online catalog of human genes and disorders
Watkins D, Rosenblatt DS. Update and new concepts in vitamin responsive disorders of folate transport and metabolism. J Inherit Metab Dis. 2012; 35(4): 665-70.