Conditions Carnitine Palmitoyltransferase I Deficiency

Carnitine palmitoyltransferase I deficiency (CPT-1A) is a condition in which the body is unable to break down certain fats. It is considered a fatty acid oxidation condition because people affected with CPT-1A are unable to change some of the fats they eat and store in their body into the energy the body needs to function. This can cause too many unused fatty acids to build up in the body. Detecting the condition early and beginning treatment can often prevent the severe outcomes of CPT-1A.

Condition Type

Fatty Acid Oxidation Disorders


Carnitine palmitoyltransferase I deficiency (CPT-1A) is a rare condition. Less than 50 individuals have been reported to have CPT-1A. The condition is more common in certain ethnic groups, including in the Hutterite population of North America and in the Inuit people of Alaska and Canada. CPT-1A is found in 1 out of every 1,200 babies born in the American Hutterite population.

Also known as

  • CPT-IA
  • Carnitine palmitoyltransferase deficiency- type IA
  • CPT-1 deficiency
  • Arctic Variant CPT-1A

Follow-Up Testing

Your baby’s doctor may ask you if your baby is showing any of the signs of CPT-1A (see Early Signs below). If your baby has certain signs, your baby’s doctor may suggest starting immediate treatment.

If your baby’s newborn screening result for carnitine palmitoyltransferase I deficiency (CPT-1A) was out of the normal range, your baby’s doctor or the state screening program will contact you to arrange for your baby 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. Because the harmful effects of untreated CPT-1A can occur soon after birth, follow-up testing must be completed as soon as possible to determine whether or not your baby has the condition.

Follow-up testing will involve checking your baby’s urine, blood, and skin for signs of CPT-1A. A high amount of carnitine present for transporting fat in the blood may be a sign that your baby has CPT-1A.

About Carnitine Palmitoyltransferase I Deficiency

Early Signs

Signs of carnitine palmitoyltransferase I deficiency (CPT-1A) usually start between 8 and 18 months. Signs of CPT-1A include:

  • Sleeping longer or more often
  • Behavior changes
  • Irritability
  • Poor appetite
  • Fever
  • Diarrhea
  • Vomiting
  • Low blood sugar (known as hypoglycemia)
  • Trouble breathing
  • Seizures (epilepsy)

Many of these signs may occur when your baby eats foods that their body cannot break down. They can be triggered by long periods of time without eating, illnesses, and infections.

If your baby shows any of these signs, be sure to contact your baby’s doctor immediately.


Dietary Treatments

Your baby may need to be on a restricted diet in order to avoid certain foods that their body cannot break down. A dietician or a nutritionist can help you plan a healthy diet for your child.

Eating often can also help your baby avoid many of the signs mentioned in the Early Signs section.

Supplements and Medications

Your baby’s doctor may recommend Medium Chain Triglyceride (MCT) oil supplements for your baby. MCT oil contains fatty acids that individuals with carnitine palmitoyltransferase I deficiency (CPT-1A) can break down for energy. Talk to your baby’s doctor before starting this treatment.

Expected Outcomes

If carnitine palmitoyltransferase I deficiency (CPT-1A) is treated early, children can have healthy growth and development.

Children who do not receive treatment are at risk for learning disabilities, developmental delays, liver trouble, heart trouble, and kidney trouble.


When we eat food, enzymes help break it down. Some enzymes break down fats into their building blocks, called fatty acids. Other enzymes break down these fatty acids further to their base molecules. In carnitine palmitoyltransferase I deficiency (CPT-1A), the enzyme carnitine palmitoyltransferase 1A is not working correctly.

This enzyme’s job is to help move fatty acids into the mitochondria. Mitochondria are the energy-making factories of the cell. Carnitine palmitoyltransferase 1A attaches a special substance called carnitine to fatty acids so that they can enter the mitochondria. Without carnitine, fatty acids cannot enter the mitochondria.

Babies with CPT-1A cannot put carnitine on fatty acids, so the fatty acids cannot be broken down for energy. Fatty acids are an important source of energy for the heart, especially when sugar levels are low, such as between meals. When fatty acids cannot be broken down, high levels of ammonia accumulate in the blood. Everyone has some ammonia in the blood, but high levels can be toxic.

CPT-1A is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for CPT-1A, 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 CPT-1A 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 Carnitine Palmitoyltransferase I Deficiency

Support Services

Support groups can help connect families who have a child or other family member affected with carnitine palmitoyltransferase I deficiency (CPT-1A) with a supportive community of people who have experience and expertise in living with the condition. These organizations offer resources for affected individuals and their families, as well as for health care providers:

Accessing Care

Work with your baby’s doctor to determine the next steps for your baby’s care. Your baby’s health care provider may help you coordinate care with a doctor who specializes in metabolism, a dietician who can help plan your child’s specialized diet, and other medical resources in your community. Some children with carnitine palmitoyltransferase I deficiency (CPT-1A) have developmental delays. If you think that your baby is not meeting their developmental milestones, ask your baby's health care provider about the next steps in accessing a developmental evaluation and care.

Because CPT-1A 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 CPT-1A, 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 American College of Medical Genetics and Genomics (ACMG) 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.

Families' Experiences

Michael and Crystal are two siblings who are both affected with carnitine palmitoyltransferase I deficiency (CPT-1A). Their story shows how even individuals within the same family can have a different experience with the condition and how early diagnosis can greatly improve the future health of a child. Read their story on the FOD Family Support Group website.

References & Sources

Visit the Screening, Technology And Research in Genetics (STAR-G) Project for more information on CPT-1A

Visit MedlinePlus Genetics for more condition information

ACT Sheets

Healthcare professionals can learn more about confirmatory testing by reading the American College of Medical Genetics and Genomics' Algorithm for Diagnosis and ACT Sheet, a guide for follow-up after newborn screening. You can visit this page of the ACMG website here.

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