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


Reviewed January 2010

What is the official name of the MPZ gene?

The official name of this gene is “myelin protein zero.”

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

What is the normal function of the MPZ gene?

The MPZ gene provides instructions for making a protein called myelin protein zero. It is the most abundant protein in myelin, a protective substance that covers nerves and promotes the efficient transmission of nerve impulses. Specialized cells called Schwann cells, which wrap around and insulate nerves, are the only cells that make myelin protein zero. Schwann cells are part of the peripheral nervous system which connects the brain and spinal cord to muscles and to sensory cells that detect sensations such as touch, pain, heat, and sound. Myelin protein zero is required for the proper formation and maintenance of myelin. This protein is an adhesion molecule, which means it acts like molecular glue. It plays a role in tightly packing the myelin around nerve cells (myelin compaction).

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

Charcot-Marie-Tooth disease - caused by mutations in the MPZ gene

Researchers have identified more than 120 MPZ gene mutations that cause a form of Charcot-Marie-Tooth disease known as type 1B. Many of these mutations change single protein building blocks (amino acids) in myelin protein zero. Other MPZ gene mutations lead to a protein that is missing one or more amino acids. The altered myelin protein zero probably cannot interact properly with other myelin components, which may disrupt the formation and maintenance of myelin. As a result, peripheral nerve cells cannot activate muscles used for movement or relay information from sensory cells back to the brain, leading to the weakness and sensory problems characteristic of Charcot-Marie-Tooth disease.

Some MPZ gene mutations cause a severe form of type 1B Charcot-Marie-Tooth disease. Symptoms begin during infancy or early childhood and include delayed development of motor skills such as walking. The early-onset forms of Charcot-Marie-Tooth disease are sometimes called Dejerine-Sottas syndrome, congenital hypomyelination, or Roussy-Levy syndrome. Researchers believe that the MPZ gene mutations that cause the severe form of the disorder probably disrupt the formation of myelin during early development.

Several mutations in the MPZ gene cause other forms of Charcot-Marie-Tooth disease known as type 2I, type 2J, and dominant intermediate D. These forms of Charcot-Marie-Tooth disease, which often do not become evident until adulthood, affect the specialized outgrowths from nerve cells (axons) that transmit impulses to muscles and other nerve cells. People with type 2J Charcot-Marie-Tooth disease may also have hearing loss and abnormalities in the opening of the eye through which light passes (the pupil). It is unclear how MPZ gene mutations cause these abnormalities.

Where is the MPZ gene located?

Cytogenetic Location: 1q23.3

Molecular Location on chromosome 1: base pairs 161,304,735 to 161,309,972

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

The MPZ gene is located on the long (q) arm of chromosome 1 at position 23.3.

The MPZ gene is located on the long (q) arm of chromosome 1 at position 23.3.

More precisely, the MPZ gene is located from base pair 161,304,735 to base pair 161,309,972 on chromosome 1.

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

Where can I find additional information about MPZ?

You and your healthcare professional may find the following resources about MPZ 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 MPZ gene or gene products?

  • CMT1B
  • HMSN1B
  • MPP
  • myelin glycoprotein P-zero
  • myelin peripheral protein
  • myelin protein zero (Charcot-Marie-Tooth neuropathy 1B)
  • P0 Glycoprotein
  • P0 Protein

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

What glossary definitions help with understanding MPZ?

acids ; adhesion molecule ; axons ; congenital ; gene ; molecule ; motor ; nervous system ; neuropathy ; peripheral ; peripheral nervous system ; protein ; pupil ; Schwann cells ; sensory cells ; syndrome

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


  • Boerkoel CF, Takashima H, Garcia CA, Olney RK, Johnson J, Berry K, Russo P, Kennedy S, Teebi AS, Scavina M, Williams LL, Mancias P, Butler IJ, Krajewski K, Shy M, Lupski JR. Charcot-Marie-Tooth disease and related neuropathies: mutation distribution and genotype-phenotype correlation. Ann Neurol. 2002 Feb;51(2):190-201. (
  • Gene Review: Charcot-Marie-Tooth Neuropathy Type 2 (
  • Grandis M, Vigo T, Passalacqua M, Jain M, Scazzola S, La Padula V, Brucal M, Benvenuto F, Nobbio L, Cadoni A, Mancardi GL, Kamholz J, Shy ME, Schenone A. Different cellular and molecular mechanisms for early and late-onset myelin protein zero mutations. Hum Mol Genet. 2008 Jul 1;17(13):1877-89. doi: 10.1093/hmg/ddn083. Epub 2008 Mar 12. (
  • Kochański A. Mutations in the Myelin Protein Zero result in a spectrum of Charcot-Marie-Tooth phenotypes. Acta Myol. 2004 May;23(1):6-9. Review. (
  • Mandich P, Fossa P, Capponi S, Geroldi A, Acquaviva M, Gulli R, Ciotti P, Manganelli F, Grandis M, Bellone E. Clinical features and molecular modelling of novel MPZ mutations in demyelinating and axonal neuropathies. Eur J Hum Genet. 2009 Sep;17(9):1129-34. doi: 10.1038/ejhg.2009.37. Epub 2009 Mar 18. (
  • NCBI Gene (
  • Niemann A, Berger P, Suter U. Pathomechanisms of mutant proteins in Charcot-Marie-Tooth disease. Neuromolecular Med. 2006;8(1-2):217-42. Review. (
  • Numakura C, Lin C, Ikegami T, Guldberg P, Hayasaka K. Molecular analysis in Japanese patients with Charcot-Marie-Tooth disease: DGGE analysis for PMP22, MPZ, and Cx32/GJB1 mutations. Hum Mutat. 2002 Nov;20(5):392-8. (
  • Shy ME. Peripheral neuropathies caused by mutations in the myelin protein zero. J Neurol Sci. 2006 Mar 15;242(1-2):55-66. Epub 2006 Jan 18. Review. (
  • Warner LE, Hilz MJ, Appel SH, Killian JM, Kolodry EH, Karpati G, Carpenter S, Watters GV, Wheeler C, Witt D, Bodell A, Nelis E, Van Broeckhoven C, Lupski JR. Clinical phenotypes of different MPZ (P0) mutations may include Charcot-Marie-Tooth type 1B, Dejerine-Sottas, and congenital hypomyelination. Neuron. 1996 Sep;17(3):451-60. (
  • Young P, Suter U. The causes of Charcot-Marie-Tooth disease. Cell Mol Life Sci. 2003 Dec;60(12):2547-60. Review. (


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: January 2010
Published: February 8, 2016