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Disease Profile

Carnitine palmitoyltransferase 2 deficiency

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset

All ages





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Carnitine palmitoyltransferase deficiency type 2; CPT2; Carnitine palmitoyltransferase II (CPT II) deficiency


Newborn Screening


Carnitine palmitoyltransferase 2 (CPT2) deficiency is a condition that prevents the body from using certain fats for energy, particularly during periods without food (fasting). There are three main types of CPT2 deficiency: a lethal neonatal form, a severe infantile hepatocardiomuscular form, and a myopathic form.[1] The neonatal and infantile forms are severe multisystemic diseases characterized by liver failure with hypoketotic hypoglycemia (extremely low levels of ketones (substances produced when fat cells break down in the blood) and low blood sugar), cardiomyopathy, seizures, and early death. The myopathic form is characterized by exercise-induced muscle pain and weakness and occasional myoglobinuria (rust-colored urine indicating breakdown of muscle tissue).[2] Mutations in the CPT2 gene cause CPT2 deficiency. It is inherited in an autosomal recessive pattern.[1] Treatment is based on avoidance of prolonged fasting and a low-fat and high-carbohydrate diet.[3]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Muscle weakness
Muscular weakness
Reduced carnitine O-palmitoyltransferase level
30%-79% of people have these symptoms
Decreased plasma free carnitine
Decreased plasma total carnitine
Elevated plasma acylcarnitine levels
Elevated serum creatine kinase
Elevated blood creatine phosphokinase
Elevated circulating creatine phosphokinase
Elevated creatine kinase
Elevated serum CPK
Elevated serum creatine phosphokinase
High serum creatine kinase
Increased CPK
Increased creatine kinase
Increased creatine phosphokinase
Increased serum CK
Increased serum creatine kinase
Increased serum creatine phosphokinase

[ more ]

Exercise intolerance
Decreased ability to exercise
Inability to exercise

[ more ]

Exercise-induced myalgia
Exercise-induced muscle pain
Muscle pain on exercise
Muscle pain with exercise
Muscle pain, exercise-induced

[ more ]

Elevated lipids in blood
Muscle tissue disease
Red-brown urine
5%-29% of people have these symptoms
Cold-induced muscle cramps
Episodic abdominal pain
Exercise-induced muscle cramps
Exercise-induced muscle cramping
Muscle cramps following exercise
Muscle cramps on exercise
Muscle cramps on exertion
Muscle cramps with exertion

[ more ]

Enlarged liver
Intermittent painful muscle spasms
Renal tubular epithelial necrosis
Breakdown of skeletal muscle
Stage 5 chronic kidney disease
Tubulointerstitial nephritis
1%-4% of people have these symptoms
Abnormality of the basal ganglia
Agenesis of corpus callosum
Abnormal heart rate
Heart rhythm disorders
Irregular heart beat
Irregular heartbeat

[ more ]

Disease of the heart muscle
Cerebellar vermis hypoplasia
Cerebral calcification
Abnormal deposits of calcium in the brain
Cystic renal dysplasia
Hepatic calcification
Hepatic failure
Liver failure
Too much cerebrospinal fluid in the brain
Hypoketotic hypoglycemia
Neonatal respiratory distress
Infantile respiratory distress
Newborn respiratory distress
Respiratory distress, neonatal

[ more ]

Fewer and broader ridges in brain
Polycystic kidney dysplasia
More grooves in brain


Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Newborn Screening

  • An ACTion (ACT) sheet is available for this condition that describes the short-term actions a health professional should follow when an infant has a positive newborn screening result. ACT sheets were developed by experts in collaboration with the American College of Medical Genetics.
  • An Algorithm flowchart is available for this condition for determining the final diagnosis in an infant with a positive newborn screening result. Algorithms are developed by experts in collaboration with the American College of Medical Genetics.
  • Baby's First Test is the nation's newborn screening education center for families and providers. This site provides information and resources about screening at the local, state, and national levels and serves as the Clearinghouse for newborn screening information.
  • The Newborn Screening Coding and Terminology Guide created by the National Library of Medicine (NLM) at the National Institutes of Health (NIH) promotes and facilitates the use of electronic health data standards in recording and transmitting newborn screening test results. The Web site includes standard codes and terminology for newborn tests and conditions for which they screen, and links to related sites. Click on the link to view details for this condition.
  • National Newborn Screening and Global Resource Center (NNSGRC) provides information and resources in the area of newborn screening and genetics to benefit health professionals, the public health community, consumers and government officials.
  • Simone Albers, et al. Detection of Neonatal Carnitine Palmitoyltransferase II Deficiency by Expanded Newborn Screening With Tandem Mass Spectrometry. Pediatrics, Jun 2001;107:e103.


    The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

    Management Guidelines

    • Orphanet Emergency Guidelines is an article which is expert-authored and peer-reviewed that is intended to guide health care professionals in emergency situations involving this condition.


      Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

      Organizations Supporting this Disease

        Organizations Providing General Support

          Learn more

          These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

          Where to Start

          • Genetics Home Reference (GHR) contains information on Carnitine palmitoyltransferase 2 deficiency. This website is maintained by the National Library of Medicine.
          • The Screening, Technology And Research in Genetics (STAR-G) Project has a fact sheet on this condition, which was written specifically for families that have received a diagnosis as a result of newborn screening. This fact sheet provides general information about the condition and answers questions that are of particular concern to parents.

            In-Depth Information

            • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
            • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
            • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
            • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
            • PubMed is a searchable database of medical literature and lists journal articles that discuss Carnitine palmitoyltransferase 2 deficiency. Click on the link to view a sample search on this topic.


              1. Carnitine palmitoyltransferase II deficiency. Genetics Home Reference (GHR). November 2010; https://www.ghr.nlm.nih.gov/condition/carnitine-palmitoyltransferase-ii-deficiency. Accessed 5/29/2012.
              2. Wieser T. Carnitine Palmitoyltransferase II Deficiency. GeneReviews. October 2011; https://www.ncbi.nlm.nih.gov/books/NBK1253/. Accessed 5/29/2012.
              3. Bennett M, Stanley C. Carnitine palmitoyl transferase II deficiency. Orphanet. April2010; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=157. Accessed 5/29/2012.