GTR Home > Tests > Alzheimer Disease Type 3


Test order codeHelp: PSEN1

Test name


Alzheimer Disease Type 3 (PSEN1)

Purpose of the test


This is a clinical test intended for Help: Mutation Confirmation, Pre-symptomatic, Risk Assessment



1condition tested. Click Indication tab for more information.


Molecular Genetics
CSequence analysis of the entire coding region
Bi-directional Sanger Sequence Analysis
  • Applied Biosystems 3730 capillary sequencing instrument

Summary of what tested

1 genes and variants. Click Methodology tab for more information.

Genes and variants

Clinical validity


EOFAD is diagnosed in families with multiple affected individuals with mean age of onset before 65 years and/or with a documented disease-causing mutation in one of the genes known to be associated with EOFAD. The three clinically indistinguishable subtypes of EOFAD based on the underlying genetic mechanism are: Alzheimer disease type 1 (AD1), caused by mutations in APP (10%-15% of EOFAD); Alzheimer disease type 3 (AD3), caused by mutations in PSEN1, (30%-70% of EOFAD); and Alzheimer disease type 4 (AD4), caused by mutations in PSEN2 (<5% of EOFAD). Kindreds with autosomal dominant EOFAD with no identifiable mutations in PSEN1, PSEN2, or APP have been described; thus, it is likely that mutations in additional genes are causative. Molecular genetic testing for PSEN1, PSEN2, and APP is available on a clinical basis.


Not provided

Clinical utility


Establish or confirm diagnosis

  • Walker ES, Martinez M, Brunkan AL, Goate A. Presenilin 2 familial Alzheimer's disease mutations result in partial loss of function and dramatic changes in Abeta 42/40 ratios. J Neurochem. 2005;92:294–301. Wijsman EM, Daw EW, Yu X, Steinbart EJ, Nochlin D, Bird TD, Schellenberg GD. APOE and other loci affect age-at-onset in Alzheimer's disease families with PS2 mutation. Am J Med Genet B Neuropsychiatr Genet. 2005;132B:14–20. Wong PC, Zheng H, Chen H, Becher MW, Sirinathsinghji DJ, Trumbauer ME, Chen HY, Price DL, Van der Ploeg LH, Sisodia SS. Presenilin 1 is required for Notch1 and DII1 expression in the paraxial mesoderm. Nature. 1997;387:288–92. Yescas P, Huertas-Vazquez A, Villarreal-Molina MT, Rasmussen A, Tusié-Luna MT, López M, Canizales-Quinteros S, Alonso ME. Founder effect for the Ala431Glu mutation of the presenilin 1 gene causing early-onset Alzheimer's disease in Mexican families. Neurogenetics. 2006;7:195–200. Yu CE, Marchani E, Nikisch G, Müller U, Nolte D, Hertel

How to order


Not provided

Clinical resources

Practice guidelines

  • EFNS, 2010
    EFNS guidelines for the diagnosis and management of Alzheimer&apos;s disease.
  • AHRQ, 2010
    Preventing Alzheimer&apos;s disease and cognitive decline.

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