Mutations

PSEN1 V391F

Overview

Pathogenicity: Alzheimer's Disease : Pathogenic
ACMG/AMP Pathogenicity Criteria: PS3, PS4, PM1, PM2, PM5, PP2, PP3
Clinical Phenotype: Alzheimer's Disease
Reference Assembly: GRCh37/hg19
Position: Chr14:73683875 G>T
dbSNP ID: rs63751066
Coding/Non-Coding: Coding
DNA Change: Substitution
Expected RNA Consequence: Substitution
Expected Protein Consequence: Missense
Codon Change: GTT to TTT
Reference Isoform: PSEN1 Isoform 1 (467 aa)
Genomic Region: Exon 11

Findings

This mutation was first identified in a French family with three affected members, spanning three generations, having probable or definite AD with onset between 42 and 45 years of age (Raux et al., 2005). The screen included 31 families in whom the coding regions of the PSEN1 and PSEN2 genes, as well as exons 16 and 17 of the APP gene, were sequenced from genomic DNA.

The mutation was subsequently found in two additional French families with AD diagnosed in seven and two members each, with ages of onset ranging between 54 and 55, and 45–50 (Wallon et al., 2012). In the family with seven affected members, the mutation was reported to co-segregate with disease.

This variant was absent from the gnomAD variant database (gnomAD v2.1.1, August 2021).

Neuropathology
Unknown

Biological Effect
In an in vitro assay using purified proteins to test the ability of this mutant to cleave the APP-C99 substrate, production of Aβ40 was reduced and the Aβ42/Aβ40 ratio was elevated (Sun et al., 2017). Several in silico algorithms (SIFT, Polyphen-2, LRT, MutationTaster, MutationAssessor, FATHMM, PROVEAN, CADD, REVEL, and Reve in the VarCards database) predicted this variant is damaging (Xiao et al., 2021).

Pathogenicity

Alzheimer's Disease : Pathogenic

This variant fulfilled the following criteria based on the ACMG/AMP guidelines. See a full list of the criteria in the Methods page.

PS3-S

Well-established in vitro or in vivo functional studies supportive of a damaging effect on the gene or gene product.

PS4-M

The prevalence of the variant in affected individuals is significantly increased compared to the prevalence in controls. V391F: The variant was reported in 3 or more unrelated patients with the same phenotype, and absent from controls.

PM1-M

Located in a mutational hot spot and/or critical and well-established functional domain (e.g. active site of an enzyme) without benign variation.

PM2-M

Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium. *Alzforum uses the gnomAD variant database.

PM5-M

Novel missense change at an amino acid residue where a different missense change determined to be pathogenic has been seen before.

PP2-P

Missense variant in a gene that has a low rate of benign missense variation and where missense variants are a common mechanism of disease.

PP3-P

Multiple lines of computational evidence support a deleterious effect on the gene or gene product (conservation, evolutionary, splicing impact, etc.). *In most cases, Alzforum applies this criterion when the variant’s PHRED-scaled CADD score is greater than or equal to 20.

Pathogenic (PS, PM, PP) Benign (BA, BS, BP)
Criteria Weighting Strong (-S) Moderate (-M) Supporting (-P) Supporting (-P) Strong (-S) Strongest (BA)

Last Updated: 22 Feb 2022

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References

Paper Citations

  1. . Molecular diagnosis of autosomal dominant early onset Alzheimer's disease: an update. J Med Genet. 2005 Oct;42(10):793-5. Epub 2005 Jul 20 PubMed.
  2. . The French series of autosomal dominant early onset Alzheimer's disease cases: mutation spectrum and cerebrospinal fluid biomarkers. J Alzheimers Dis. 2012 Jan 1;30(4):847-56. PubMed.
  3. . Analysis of 138 pathogenic mutations in presenilin-1 on the in vitro production of Aβ42 and Aβ40 peptides by γ-secretase. Proc Natl Acad Sci U S A. 2017 Jan 24;114(4):E476-E485. Epub 2016 Dec 5 PubMed.
  4. . APP, PSEN1, and PSEN2 Variants in Alzheimer's Disease: Systematic Re-evaluation According to ACMG Guidelines. Front Aging Neurosci. 2021;13:695808. Epub 2021 Jun 18 PubMed.

External Citations

  1. gnomAD v2.1.1

Further Reading

No Available Further Reading

Protein Diagram

Primary Papers

  1. . Molecular diagnosis of autosomal dominant early onset Alzheimer's disease: an update. J Med Genet. 2005 Oct;42(10):793-5. Epub 2005 Jul 20 PubMed.

Other mutations at this position

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