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PSEN2 gene

presenilin 2

Normal Function

The PSEN2 gene provides instructions for making a protein called presenilin 2. Presenilin 2 helps process proteins that transmit chemical signals from the cell membrane into the nucleus. Once in the nucleus, these signals turn on (activate) genes that are important for cell growth and maturation.

Presenilin 2 is best known for its role in processing amyloid precursor protein, which is found in the brain and other tissues. Research suggests that presenilin 2 works together with other enzymes to cut amyloid precursor protein into smaller segments (peptides). One of these peptides is called soluble amyloid precursor protein (sAPP), and another is called amyloid beta peptide. Recent evidence suggests that sAPP has growth-promoting properties and may play a role in the formation of neurons in the brain both before and after birth. Other functions of sAPP and amyloid beta peptide are under investigation.

Health Conditions Related to Genetic Changes

Alzheimer's disease

At least 11 mutations in the PSEN2 gene have been shown to cause early-onset Alzheimer's disease. Mutations in this gene account for less than 5 percent of all early-onset cases of the disorder.

Two of the most common PSEN2 mutations that cause early-onset Alzheimer's disease change single protein building blocks (amino acids) used to make presenilin 2. One mutation replaces the amino acid asparagine with the amino acid isoleucine at position 141 (written as Asn141Ile or N141I). The other mutation changes the amino acid methionine to the amino acid valine at position 239 (written as Met239Val or M239V). These mutations appear to disrupt the processing of amyloid precursor protein, leading to the overproduction of amyloid beta peptide. This protein fragment can build up in the brain and form clumps called amyloid plaques that are characteristic of Alzheimer's disease. A buildup of toxic amyloid beta peptide and amyloid plaques may lead to the death of neurons and the progressive signs and symptoms of this disorder.

More About This Health Condition

Familial dilated cardiomyopathy

MedlinePlus Genetics provides information about Familial dilated cardiomyopathy

More About This Health Condition

Other Names for This Gene

  • AD3-like protein
  • AD3L
  • AD3LP
  • AD4
  • AD5
  • Alzheimer's disease 3-like
  • E5-1
  • presenilin 2 (Alzheimer disease 4)
  • PS2 protein (alzheimer-associated)
  • PSNL2
  • STM2

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


  • Bertram L, Tanzi RE. The current status of Alzheimer's disease genetics: what do we tell the patients? Pharmacol Res. 2004 Oct;50(4):385-96. doi: 10.1016/j.phrs.2003.11.018. Citation on PubMed
  • Cordy JM, Hooper NM, Turner AJ. The involvement of lipid rafts in Alzheimer's disease. Mol Membr Biol. 2006 Jan-Feb;23(1):111-22. doi: 10.1080/09687860500496417. Citation on PubMed
  • George-Hyslop PS, Rossor M. Alzheimer's disease. Unravelling the disease process. Lancet. 2001 Dec;358 Suppl:S1. doi: 10.1016/s0140-6736(01)07014-3. No abstract available. Citation on PubMed
  • Harman D. Alzheimer's disease pathogenesis: role of aging. Ann N Y Acad Sci. 2006 May;1067:454-60. doi: 10.1196/annals.1354.065. Citation on PubMed
  • Papassotiropoulos A, Fountoulakis M, Dunckley T, Stephan DA, Reiman EM. Genetics, transcriptomics, and proteomics of Alzheimer's disease. J Clin Psychiatry. 2006 Apr;67(4):652-70. doi: 10.4088/jcp.v67n0418. Citation on PubMed or Free article on PubMed Central
  • Rocchi A, Pellegrini S, Siciliano G, Murri L. Causative and susceptibility genes for Alzheimer's disease: a review. Brain Res Bull. 2003 Jun 30;61(1):1-24. doi: 10.1016/s0361-9230(03)00067-4. Citation on PubMed
  • Selkoe DJ. Alzheimer's disease: genes, proteins, and therapy. Physiol Rev. 2001 Apr;81(2):741-66. doi: 10.1152/physrev.2001.81.2.741. Citation on PubMed
  • St George-Hyslop PH. Genetic factors in the genesis of Alzheimer's disease. Ann N Y Acad Sci. 2000;924:1-7. doi: 10.1111/j.1749-6632.2000.tb05552.x. Citation on PubMed
  • Thinakaran G, Parent AT. Identification of the role of presenilins beyond Alzheimer's disease. Pharmacol Res. 2004 Oct;50(4):411-8. doi: 10.1016/j.phrs.2003.12.026. 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.