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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed November 2010

What is the official name of the CPT2 gene?

The official name of this gene is “carnitine palmitoyltransferase 2.”

CPT2 is the gene's official symbol. The CPT2 gene is also known by other names, listed below.

What is the normal function of the CPT2 gene?

The CPT2 gene provides instructions for making an enzyme called carnitine palmitoyltransferase 2. This enzyme is essential for fatty acid oxidation, a multistep process that breaks down (metabolizes) fats and converts them into energy. Fatty acid oxidation takes place within mitochondria, which are the energy-producing centers in cells. A group of fats called long-chain fatty acids must be attached to a substance known as carnitine to enter mitochondria. Once these fatty acids are inside mitochondria, carnitine palmitoyltransferase 2 removes the carnitine and adds a substance called coenzyme A. Long-chain fatty acids must be joined to coenzyme A before they can be metabolized to produce energy. Fatty acids are a major source of energy for the heart and muscles. During periods of fasting, fatty acids are also an important energy source for the liver and other tissues.

How are changes in the CPT2 gene related to health conditions?

carnitine palmitoyltransferase II deficiency - caused by mutations in the CPT2 gene

More than 70 mutations in the CPT2 gene have been found to cause carnitine palmitoyltransferase II (CPT II) deficiency. These mutations lead to reduced activity of carnitine palmitoyltransferase 2. Mutations that lead to extremely reduced enzyme activity typically cause the more severe forms of CPT II deficiency (a lethal neonatal form and a severe infantile hepatocardiomuscular form), while those that result in partially reduced enzyme activity usually lead to a less severe myopathic form of the disorder. The most common CPT2 gene mutation replaces the protein building block (amino acid) serine with the amino acid leucine at position 113 (written as Ser113Leu or S113L) in the enzyme. This mutation accounts for about 60 percent of the mutations that cause the myopathic form of CPT II deficiency.

Without enough functioning carnitine palmitoyltransferase 2, long-chain fatty acids are not properly processed after they enter mitochondria and cannot be metabolized to produce energy. Reduced energy production can lead to some of the features of CPT II deficiency, such as muscle pain and weakness, low blood sugar (hypoglycemia), and low levels of the products of fat breakdown (hypoketosis). Fatty acids and long-chain acylcarnitines (fatty acids still attached to carnitine) may also build up in cells and damage the liver, heart, and muscles. This abnormal buildup causes the other signs and symptoms of the disorder.

Where is the CPT2 gene located?

Cytogenetic Location: 1p32

Molecular Location on chromosome 1: base pairs 53,196,429 to 53,214,197

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The CPT2 gene is located on the short (p) arm of chromosome 1 at position 32.

The CPT2 gene is located on the short (p) arm of chromosome 1 at position 32.

More precisely, the CPT2 gene is located from base pair 53,196,429 to base pair 53,214,197 on chromosome 1.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about CPT2?

You and your healthcare professional may find the following resources about CPT2 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the CPT2 gene or gene products?

  • CPT II

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding CPT2?

acids ; amino acid ; breakdown ; carnitine ; coenzyme A ; deficiency ; enzyme ; fasting ; fatty acids ; gene ; hypoglycemia ; leucine ; mitochondria ; mutation ; neonatal ; oxidation ; protein ; serine

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Corti S, Bordoni A, Ronchi D, Musumeci O, Aguennouz M, Toscano A, Lamperti C, Bresolin N, Comi GP. Clinical features and new molecular findings in Carnitine Palmitoyltransferase II (CPT II) deficiency. J Neurol Sci. 2008 Mar 15;266(1-2):97-103. Epub 2007 Oct 23. (
  • Deschauer M, Wieser T, Zierz S. Muscle carnitine palmitoyltransferase II deficiency: clinical and molecular genetic features and diagnostic aspects. Arch Neurol. 2005 Jan;62(1):37-41. (
  • Illsinger S, Lücke T, Peter M, Ruiter JP, Wanders RJ, Deschauer M, Handig I, Wuyts W, Das AM. Carnitine-palmitoyltransferase 2 deficiency: novel mutations and relevance of newborn screening. Am J Med Genet A. 2008 Nov 15;146A(22):2925-8. doi: 10.1002/ajmg.a.32545. (
  • Isackson PJ, Bennett MJ, Lichter-Konecki U, Willis M, Nyhan WL, Sutton VR, Tein I, Vladutiu GD. CPT2 gene mutations resulting in lethal neonatal or severe infantile carnitine palmitoyltransferase II deficiency. Mol Genet Metab. 2008 Aug;94(4):422-7. doi: 10.1016/j.ymgme.2008.05.002. Epub 2008 Jun 11. (
  • Longo N, Amat di San Filippo C, Pasquali M. Disorders of carnitine transport and the carnitine cycle. Am J Med Genet C Semin Med Genet. 2006 May 15;142C(2):77-85. Review. (
  • NCBI Gene (
  • Olpin SE, Afifi A, Clark S, Manning NJ, Bonham JR, Dalton A, Leonard JV, Land JM, Andresen BS, Morris AA, Muntoni F, Turnbull D, Pourfarzam M, Rahman S, Pollitt RJ. Mutation and biochemical analysis in carnitine palmitoyltransferase type II (CPT II) deficiency. J Inherit Metab Dis. 2003;26(6):543-57. (
  • Ramsay RR, Zammit VA. Carnitine acyltransferases and their influence on CoA pools in health and disease. Mol Aspects Med. 2004 Oct-Dec;25(5-6):475-93. Review. (
  • Sigauke E, Rakheja D, Kitson K, Bennett MJ. Carnitine palmitoyltransferase II deficiency: a clinical, biochemical, and molecular review. Lab Invest. 2003 Nov;83(11):1543-54. Review. (
  • Ørngreen MC, Dunø M, Ejstrup R, Christensen E, Schwartz M, Sacchetti M, Vissing J. Fuel utilization in subjects with carnitine palmitoyltransferase 2 gene mutations. Ann Neurol. 2005 Jan;57(1):60-6. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: November 2010
Published: February 1, 2016