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MPZ gene

myelin protein zero

Normal Function

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. Myelin protein zero is produced by specialized cells called Schwann cells, which wrap around and insulate peripheral nerves. Peripheral nerves connect 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).

Health Conditions Related to Genetic Changes

Charcot-Marie-Tooth disease

Researchers have identified more than 120 MPZ gene mutations that cause a form of Charcot-Marie-Tooth disease known as type 1B. Charcot-Marie-Tooth syndrome is a disorder characterized by muscle weakness and sensory problems, especially in the hands and feet. Many of the MPZ gene mutations that cause Charcot-Marie-Tooth syndrome change single protein building blocks (amino acids) in myelin protein zero. Other 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 myelin compaction. As a result, peripheral nerves cannot trigger muscle 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. This form of Charcot-Marie-Tooth disease is 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.

More About This Health Condition

Other Names for This Gene

  • CMT1B
  • CMT2I
  • CMT2J
  • HMSN1B
  • MPP
  • myelin glycoprotein P-zero
  • myelin peripheral protein
  • myelin protein zero (Charcot-Marie-Tooth neuropathy 1B)
  • P0 Glycoprotein
  • P0 Protein

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Berger P, Niemann A, Suter U. Schwann cells and the pathogenesis of inherited motor and sensory neuropathies (Charcot-Marie-Tooth disease). Glia. 2006 Sep;54(4):243-57. doi: 10.1002/glia.20386. Citation on PubMed
  • Bird TD. Charcot-Marie-Tooth Hereditary Neuropathy Overview. 1998 Sep 28 [updated 2024 Apr 25]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from Citation on PubMed
  • 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. doi: 10.1002/ana.10089. Citation on PubMed
  • Brennan KM, Bai Y, Shy ME. Demyelinating CMT--what's known, what's new and what's in store? Neurosci Lett. 2015 Jun 2;596:14-26. doi: 10.1016/j.neulet.2015.01.059. Epub 2015 Jan 24. Citation on PubMed
  • 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. Citation on PubMed
  • Kochanski A. Mutations in the Myelin Protein Zero result in a spectrum of Charcot-Marie-Tooth phenotypes. Acta Myol. 2004 May;23(1):6-9. Citation on PubMed
  • 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. Citation on PubMed or Free article on PubMed Central
  • Niemann A, Berger P, Suter U. Pathomechanisms of mutant proteins in Charcot-Marie-Tooth disease. Neuromolecular Med. 2006;8(1-2):217-42. doi: 10.1385/nmm:8:1-2:217. Citation on PubMed
  • 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. doi: 10.1002/humu.10134. Citation on PubMed
  • Shy ME. Peripheral neuropathies caused by mutations in the myelin protein zero. J Neurol Sci. 2006 Mar 15;242(1-2):55-66. doi: 10.1016/j.jns.2005.11.015. Epub 2006 Jan 18. Citation on PubMed
  • 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. doi: 10.1016/s0896-6273(00)80177-4. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.