FATTY ACID DISORDER

Disorder Name:  CarnitineThis is a natural substance found in muscle cells. It helps the body make energy from the fat in food and the fat stored in the body. It also helps the cells get rid of harmful wastes made during the breakdown of fat. Carnitine supplements may be used as a treatment for some metabolic disorders. palmitoyl transferase deficiency, type 1A
Acronym:  CPT1A
Download PDF

• What is CPT1A deficiency?
• What causes CPT1A deficiency?
• If CPT1A deficiency is not treated, what problems occur?
• What is the treatment for CPT1A deficiency?
• What happens when CPT1A deficiency is treated?
• What causes the CPT1A enzyme to be absent or not working correctly?
• How is CPT1A deficiency inherited?
• Is genetic testing available?
• What other testing is available?
• Can you test during a future pregnancy?
• Can other members of the family have CPT1A deficiency or be carriers?
• Can other family members be tested?
• How many people have CPT1A deficiency?
• Does CPT1A deficiency happen more often in a certain ethnic group?
• Does CPT1A deficiency go by any other names?
• Where can I find more information?

This fact sheet contains general information about CPT1A deficiency. Every child is different and some of this information may not apply to your child specifically. Not all is known about CPT1A deficiency and, at present, there is no standard treatment plan. Certain treatments may be recommended for some children but not others. Children with CPT1A deficiency should be followed by a metabolic doctor in addition to their primary doctor.

WHAT IS CPT1A DEFICIENCY?

CPT1A deficiency stands for “carnitine palmitoyl transferase – type 1A deficiency.” It is one type of fatty acid oxidationThis is the process used by the body to change fatty acids, the building blocks of fat, into energy. It happens in the mitochondria – the small energy-producing parts found in each cell of the body. disorder. People with CPT1A deficiency have problems breaking down fat into energy for the body.

Fatty Acid Oxidation Disorders: Fatty acid oxidation disorders (FAODs)This is a group of rare inherited conditions. FAODs are caused by missing or non-working enzymes. Normally, many enzymes are used by the body to break down fat into energy. In people with FAODs, one of these enzymes is not working and fat cannot be used for energy. If these conditions are not treated, they can lead to serious health problems. are a group of rare inheritedAcquiring a trait from one’s parents. Most traits, such as eye color or hair color, are inherited from a parent through genes. conditions. They are caused by enzymes that do not work properly. A number of enzymesA molecule that helps chemical reactions take place. For example, enzymes in the stomach speed up the process of breaking down food. Each enzyme can participate in many chemical reactions without changing or being used up. are needed to break down fats in the body (a process called fatty acid oxidation). Problems with any of these enzymes can cause a fatty acid oxidation disorder. People with FAODs cannot properly break down fatFat is one of the three main nutrients in food (carbohydrates, fat, protein). Some foods that contain fat are butter, margarine, oils, nuts, meats, poultry, fish and some dairy products. Extra calories from food are stored as body fat. Stored body fat provides the body with a reserve supply of energy. from either the food they eat or from fat stored in their bodies. The symptoms and treatment vary between different FAODs. They can also vary from person to person with the same FAOD. See the fact sheets for each specific FAOD. FAODs are inherited in an autosomal recessive manner and affect both males and females.

WHAT CAUSES CPT1A DEFICIENCY?

CPT1A deficiency is caused by problems with the enzyme, “carnitine palmitoyl transferase 1A” (CPT1A). In people with CPT1A deficiency, the CPT1A enzyme is either missing or not working properly. This enzyme’s job is to help change certain fats in the food we eat into energy. It also helps break down fat already stored in the body.

Energy from fat keeps us going whenever our bodies run low of their main source of energy, a type of sugar called glucoseThis is a type of sugar made from the carbohydrates in food. Glucose is found in the blood. It is the main source of energy for the body and brain.. Our bodies rely on fat when we don’t eat for a stretch of time – like when we miss a meal or when we sleep.

When the CPT1A enzyme is missing or not working, the body cannot use fat for energy, and must rely solely on glucose. Although glucose is a good source of energy, there is a limited amount available. Once the glucose has been used up, the body tries to use fat without success. This leads to low blood sugar, called hypoglycemiaThis happens when there is too little sugar (glucose) in the blood. It may cause a person to feel nervous, shaky, weak, or sweaty. It may also cause headache, blurred vision, and hunger. If left untreated, it can cause unconsciousness (coma) and sometimes even death., and to the build up of harmful substances in the blood

IF CPT1A DEFICIENCY IS NOT TREATED, WHAT PROBLEMS OCCUR?

CPT1A deficiency can cause episodes of illness caused metabolic crises. Children with CPT1A deficiency usually start showing symptoms between the ages of 8 and 18 months, although effects can occur earlier. Some of the first signs of a metabolic crisisThis is a serious health condition caused by low blood sugar and the build-up of toxic substances in the blood. Symptoms of a metabolic crisis are poor appetite, nausea, vomiting, diarrhea, extreme sleepiness, irritable mood and behavior changes. If not treated, breathing problems, seizures, coma, and sometimes even death can occur.Metabolic crises happen more often in people with certain metabolic disorders (some fatty acid oxidation disorders, amino acid disorders, and organic acid disorders). They are often triggered by things like illness or infection, going without food for a long time, and, in some cases, heavy exercise. are:

• extreme sleepiness
• behavior changes
• irritable mood
• poor appetite

Other symptoms then follow:

• fever
• diarrhea
• vomiting
• hypoglycemia
• high levels of ammonia in the blood

If a metabolic crisis is not treated, a child with CPT1A deficiency can develop:

• breathing problems
• seizuresThese are also called "convulsions" or "fits." During a seizure, a person loses consciousness and control of his or her muscles. It may also cause involuntary movements. Seizures can happen for many reasons. Some causes are metabolic disorders, a metabolic crisis, brain injury, and infection.
• comaThis is a sleep-like condition from which a person cannot be awakened. People in a coma are unconscious. A coma can be caused by many things. Two causes are untreated low blood sugar (hypoglycemia) and a metabolic crisis., sometimes leading to death

Between episodes of metabolic crisis, people with CPT1A deficiency are usually healthy. However, repeated episodes may cause brain damage that can result in learning problems or intellectual disabilities.

Symptoms often happen after having nothing to eat for more than a few hours. During long periods without eating, the glucose in the body is used up. This causes hypoglycemia. The body then tries to use fat for energy, leading to the build up of harmful substances in the blood. Symptoms are also more likely when a person with CPT1A deficiency gets sick or has an infection. Prompt emergency treatment of infants and children with CPT1A can help prevent metabolic crises or lessen their severity.

Babies and children who are not treated can have:

• learning problems
• delays in walking and other motor skills
• liver, heart, or kidney problems

Some children with CPT1A deficiency have never had symptoms and are only found to be affected after a brother or sister has been diagnosed. CPT1A deficiency in people of Inuit (Native American Alaskan) or First Nation (Canada) ethnicity very rarely causes symptoms.

WHAT IS THE TREATMENT FOR CPT1A DEFICIENCY?  

Your baby’s primary doctor will work with a metabolic doctor to care for your child. Your doctor may also suggest that you meet with a dietician familiar with CPT1A deficiency.

Certain treatments may be advised for some children but not others. When necessary, treatment is usually needed throughout life. The following are treatments sometimes recommended for children with CPT1A deficiency:

1.  Avoid going a long time without food 
Infants and young children with CPT1A deficiency need to eat frequently to prevent a metabolic crisis. Your metabolic doctorThis is a doctor or medical geneticist who has special training in diagnosing and treating metabolic disorders. They often work in university hospitals or large medical centers. will tell you how often your child needs to be fed.  In general, it is often suggested that infants be fed every four to six hours. Some babies need to eat even more frequently than this. Your metabolic doctor and dieticianThis is a person with special training in food and nutrition. A registered dietician (RD) has met the necessary educational requirements and has passed a national examination. If your child has a metabolic disorder, it is important for you to work with a registered dietician. They help create healthy food plans for people with metabolic disorders or other special needs. will give you an appropriate feeding plan for your infant. Your doctor will also give you a ‘sick day’ plan tailored to your child’s needs for you to follow during illnesses or other times when your child will not eat.

Your metabolic doctor will continue to advise you on how often your child should eat as he or she gets older.  When they are well, many teens and adults with CPT1A deficiency can go without food for up to 12 hours without problems. The other treatments usually need to be continued throughout life.

2.  Diet
Sometimes a low-fat, high carbohydrate food plan is recommended. CarbohydratesThis is one of the three types of nutrients in food (carbohydrates, fats, proteins). Sugars and starches are the most important types of carbohydrates. They are broken down by the body into glucose, the main source of energy for the body. Carbohydrates are found in foods such as: bread, cereal, pasta, grains, fruits and vegetables. Milk and dairy products, fruit drinks, sugar, candy, and sweet desserts also contain carbohydrates. give the body many types of sugar that can be used as energy. In fact, for children needing this treatment, most food in the diet should be carbohydrates (bread, pasta, fruit, vegetables, etc.) and protein (lean meat and low-fat dairy foods). Any diet changes should be made under the guidance of a dietician experienced with CPT1A deficiency.

People with CPT1A deficiency cannot use certain building blocks of fat called “long-chain fatty acidsThis is one of many types of fatty acids, the building blocks of fat. Long-chain fatty acids are made up of chains of 12 or more carbon atoms..”  Your dietician can help create a food plan low in these fats. Much of the rest of fat in the diet will likely be in the form of medium-chain fatty acidsThese are the building blocks of fat. Fat from food is broken down by enzymes into fatty acids. These are changed by other enzymes and are used as energy or stored as body fat. Some types of fatty acids are: short-chain, medium-chain, long-chain, and very-long chain..

Ask your doctor if your child needs to have any changes in his or her diet.

3.  Medium-Chain Triglyceride oil (MCT)
Medium Chain Triglycerides (MCT) are often used as part of the food plan for people with CPT1A deficiency. MCTs are available in MCT oil and in triheptanoin (DOJOLVI ®) – a medication made of MCTs. These supplements have medium chain fatty acidsThis is one of many types of fatty acids, the building blocks of fat. Medium-chain fatty acids are made up of chains of 4 to 12 carbon atoms. that can be used in small amounts for energy. Your metabolic doctor or dietician can tell you how to use these supplements. You will need to get a prescription from your doctor to get these MCTs supplements.

4. Call your doctor at the start of any illness
Always call your health care provider right away when your child has any of the following:

• poor appetite
• low energy or excessive sleepiness
• vomiting
• diarrhea
• an infection
• a fever

Children with CPT1A deficiency need to eat extra starchy food and drink more fluids than usual when they are sick – even if they may not feel hungry – or they could have a metabolic crisis.  Children who are sick often don’t want to eat. If they won’t or can’t eat, they may need to be treated in the hospital to prevent serious health problems. Ask your metabolic doctor if you should carry a special travel letter with medical instructions for your child’s care.

WHAT HAPPENS WHEN CPT1A DEFICIENCY IS TREATED?

With prompt and careful treatment, children with CPT1A deficiency often live healthy lives with typical growth and development. After 5 years of age, metabolic crises tend to happen less often and are not as severe.

If repeated episodes of metabolic crisis occur, there is a chance for permanent learning disabilities or intellectual disabilities.

WHAT CAUSES THE CPT1A ENZYME TO BE ABSENT OR NOT WORKING CORRECTLY?

Genes tell the body to make various enzymes. The CPT1A gene instructs the body to make the CPT1A enzyme. Everyone has two copies of the CPT1A gene. People with CPT1A deficiency have changes, also called variantsA variant is a change or alteration in a person’s DNA sequence. Variants can happen in genes and affect how the gene functions. There are different types of variants – they can be non-problem causing (benign), disease-causing (pathogenic) or of unknown significance. The term variants is now used in place of the term mutation. in both copies of their CPT1A genesA segment of DNA that contains the instructions to make a specific protein (or part of a protein). Genes are contained on chromosomes. Chromosomes, and the genes on those chromosomes, are passed on from parent to child. Errors in the DNA that make up a gene are called variants and can lead to diseases. that cause them to not work correctly. Because of the variants in the CPT1A genes, the CPT1A enzyme either does not work properly or is not made at all.

HOW IS CPT1A DEFICIENCY INHERITED?

CPT1A deficiency is inherited in an autosomal recessive manner. It affects both boys and girls equally.

Everyone has two copies of the CPT1A gene that make the CPT1A enzyme. In children with CPT1A deficiency, neither of their CPT1A genes works correctly. These children inherit one non-working CPT1A gene from each parent.

Parents of children with CPT1A deficiency are rarely affected with the disorder. Instead, each parent has a single non-working CPT1A gene for CPT1A deficiency. They are called carriersA person who has one copy of a gene mutation for a particular autosomal recessive disorder (remember genes come in pairs). Carriers are not affected by the disorder. However, they can pass on the gene variant to their children. Children who inherit two such gene variants will be affected by the disorder. The term variants is now used in place of the term mutation.. Carriers do not have the condition because their other CPT1A gene is working correctly.

When both parents are carriers for CPT1A deficiency, there is a 25% chance in each pregnancy for the child to have CPT1A deficiency. There is a 50% chance for the child to be a carrier, just like the parents. And, there is a 25% chance for the child to have two working genes.

GeneticRelating to (or due to) genes and heredity or the field of studying genes and heredity. counseling is available to families who have children with CPT1A deficiency. Genetic counselorsThese are health care providers who have special training in genetic conditions. They help families understand genetic disorders and how they are passed down. Genetic counselors offer information and support to people who have genetic conditions in their families or are concerned that they may have a child with an inherited disorder. can answer your questions about how CPT1A deficiency is inherited, choices during future pregnancies, and how to test other family members. Ask your doctor about a referral to a genetic counselor.

IS GENETIC TESTING AVAILABLE?

Genetic testing for CPT1A deficiency can be done on a blood sample. Genetic testing, also called DNA testing, looks for changes (variants) in the CPT1A genes that cause the condition. In most affected children, both gene changes can be found. However, in some children, neither or only one of the two gene changes can be found, even though we know they are present.

DNADeoxyribonucleic acid (DNA) is a molecule found in the chromosomes that carries genetic information. DNA is composed of four units (called bases) that are designated A, T, G, and C. The sequence of the bases spell out instructions for making all of the proteins needed by an organism. A gene is a section of DNA that holds the instructions for a specific protein. A change in one or more of the DNA bases making up a gene is called a mutation. Some mutations change the protein instructions and can lead to particular health problems or disorders. Each parent passes half of their chromosomes, and thus half of their DNA instructions, onto their children. It is these instructions that cause certain traits, such as eye or hair color, to be inherited. testing is not necessary to diagnose your child. It can be helpful for carrier testing or prenatal diagnosis, discussed below. Talk with your metabolic doctor or genetic counselor if you have questions about DNA testing for CPT1A deficiency.

WHAT OTHER TESTING IS AVAILABLE?

CPT1A deficiency can be confirmed by a special enzyme test on a skin sample. Your doctor or genetic counselor can answer your questions about testing for CPT1A deficiency.

CAN YOU TEST DURING A FUTURE PREGNANCY?

If both gene changes (variants) have been found in your child with CPT1A deficiency, DNA testing can be done during future pregnancies. The sample needed for this test is obtained by either CVS or amniocentesisThis is a test done during pregnancy. A needle is used to remove a small sample of fluid from the sac around the fetus. The sample can be used to test for certain genetic disorders in the fetus. Amniocentesis to test for genetic conditions is usually done between 13 and 20 weeks of pregnancy..

If DNA testing would not be helpful, testing during pregnancy can be done by an enzyme test on cells from the fetus. The sample needed for this test is obtained by either CVS or amniocentesis.

Parents may either choose to have testing during pregnancy or wait until birth to have the baby tested. Parents may also choose to use assisted reproductive techniques to decrease the chance that their future children would have CPT1A deficiency. A genetic counselor can talk to you about your choices and answer questions about prenatal testing or testing your baby after birth.

CAN OTHER MEMBERS OF THE FAMILY HAVE CPT1A DEFICIENCY OR BE CARRIERS?

Having CPT1A deficiency
The brothers and sisters of an affected baby have a chance of having CPT1A deficiency, even if they haven’t had symptoms. Finding out whether other children in the family have CPT1A deficiency is important because early treatment may prevent serious health problems. Talk to your doctor or genetic counselor about testing your other children for CPT1A deficiency.

CPT1A deficiency carriers
Brothers and sisters who are not affected with CPT1A deficiency still have a chance to be carriers like their parents. Except in special cases, carrier testing should only be done in people over 18 years of age.

If you are a parent of a child with CPT1A deficiency, your brothers and sisters have a 50% chance to be a carrier. It is important for other family members to be told that they could be carriers. There is a very small chance they are also at risk to have children with CPT1A deficiency.

Some states do not offer newborn screening for CPT1A deficiency. However, expanded newborn screeningA screening test that looks for different disorders using a small sample of blood taken from a newborn’s heel. A positive or abnormal newborn screening result means that there are slight differences that were found in the baby’s blood, and further testing is needed to figure out if the baby has a metabolic disorder. through private labs is available for babies born in states that do not screen for this condition. Your healthcare provider or genetic counselor can help you obtain expanded newborn screeningThe process of testing for disease in a person who does not show signs of having the disease (nonsymptomatic or asymptomatic person). The goal of screening is to catch the disease in its early stages..

When both parents are carriers, newborn screening results are not adequate to rule out CPT1A deficiency in a newborn baby. In this case, special diagnostic testing should be done in addition to newborn screening.

During pregnancy, women carrying fetuses with CPT1A deficiency may be at increased risk to develop serious medical problems. Some women carrying fetuses with Fatty Acid Oxidation Disorders have developed:

• excessive vomiting
• abdominal pain
• high blood pressure
• jaundiceThis is a yellow color to the skin and whites of the eyes. It is often a sign of liver damage.
• abnormal fat storage in the liver
• severe bleeding

All women with a family history of CPT1A deficiency should share this information with their obstetricians and other health care providers before and during any future pregnancies. Knowing about these risks allows better medical care and early treatment if needed.

CAN OTHER FAMILY MEMBERS BE TESTED?

Diagnostic testing for CPT1A deficiency
To make sure they do not have the condition, brothers and sisters of a child with CPT1A deficiency can have special tests done on a skin sample. DNA testing may also be done if both variants have been identified in the affected siblingA person who shares the same mother or father. A brother or sister who shares both parents is called a full sibling. A brother or sister who only shares one parent is called a half sibling..

Carrier testing for CPT1A deficiency
Carrier testing may be available to other family members. Ask your metabolic doctor or genetic counselor about carrier testing for family members.  

HOW MANY PEOPLE HAVE CPT1A DEFICIENCY?

CPT1A deficiency is found in about one in every 1,200 babies in the North American Hutterite community.  It is also more common among the Native American Inuit people of Canada and Alaska. CPT1A deficiency is rare in other ethnic groups around the world. The actual incidence is unknown.

DOES CPT1A DEFICIENCY HAPPEN MORE OFTEN IN A CERTAIN ETHNIC GROUP?

CPT1A deficiency can be seen in every ethnic group and geographical area.  However, it is more common in the North American Hutterite community and also among the Native American Inuit people of Canada and Alaska.

DOES CPT1A DEFICIENCY GO BY ANY OTHER NAMES?

CPT1A deficiency is sometimes also called:

• CPT1 deficiency
• CPT1 deficiency (liver)

There is another type of CPT deficiency called CPT1B, or “muscle type.” CPT1B is not discussed in this fact sheet.

WHERE CAN I FIND MORE INFORMATION?

Fatty Oxidation Disorders (FOD) Family Support Group
http://www.fodsupport.org

Organic Acidemia Association
http://www.oaanews.org

United Mitochondrial Disease Foundation
http://www.umdf.org

Metabolic Support UK
https://www.metabolicsupportuk.org

Baby’s First Test
http://www.babysfirsttest.org

MedlinePlus
https://medlineplus.gov/genetics/condition/carnitine-palmitoyltransferase-i-deficiency/

DOCUMENT INFO:

Created by:	www.newbornscreening.info
Reviewed by:	HI, CA, OR, and WA metabolic specialists
Review date:	September 31, 2007 April 18, 2011 June 30, 2013 February 28, 2016 April 24, 2020 March 1, 2023
Update on:	March 1, 2023

 

DISCLAIMER:

THIS INFORMATION DOES NOT PROVIDE MEDICAL ADVICE. All content (“Content”), including text, graphics, images and information are for general informational purposes only. You are encouraged to confer with your doctor or other health care professional with regard to information contained on this information sheet. After reading this information sheet, you are encouraged to review the information carefully with your doctor or other healthcare provider. The Content is not intended to be a substitute for professional medical advice, diagnosis or treatment. NEVER DISREGARD PROFESSIONAL MEDICAL ADVICE, OR DELAY IN SEEKING IT, BECAUSE OF SOMETHING YOU HAVE READ ON THIS INFORMATION SHEET. This project is supported by a grant from the MaternalHaving to do with the mother. and Child Health Bureau, Health Resources and Service Administration, Genetic Services Branch, MCH Project #:UH7MC30774-01-00 http://mchb.hrsa.gov