Mutations

PSEN1 V261L

Overview

Pathogenicity: Alzheimer's Disease : Not Classified
ACMG/AMP Pathogenicity Criteria: PM1, PM2, PP2, PP3
Clinical Phenotype: Alzheimer's Disease, Spastic Paraparesis
Reference Assembly: GRCh37/hg19
Position: Chr14:73664750 G>C
dbSNP ID: NA
Coding/Non-Coding: Coding
Mutation Type: Point, Missense
Codon Change: GTT to CTT
Reference Isoform: PSEN1 Isoform 1 (467 aa)
Genomic Region: Exon 8

Findings

This mutation was identified in a Spanish woman who developed cognitive impairment, including memory loss, as well as gait disruption secondary to spastic paraparesis, at age 40 (Jiménez-Caballero et al., 2008; Gómez-Tortosa et al., 2010). Her brother and mother developed similar symptoms in their late 40s.

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

Neuropathology
Neuropathological data are not available, but MRI of the proband’s brain showed symmetrical cortical and subcortical atrophy, particularly in the frontal lobes, and SPECT revealed bilateral temporal hypoperfusion.

Biological Effects
The biological effects of this variant are unknown, but 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). These authors classified the variant as likely pathogenic using the ACMG-AMP guidelines (Richards et al., 2015).

Pathogenicity

Alzheimer's Disease : Not Classified*

*This variant fulfilled some ACMG-AMP criteria, but it was not classified by Alzforum, because data for either a pathogenic or benign classification are lacking: only one affected carrier has been reported without co-segregation data, and the variant is absent—or very rare—in the gnomAD database.

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

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.

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. . A novel presenilin 1 mutation (V261L) associated with presenile Alzheimer's disease and spastic paraparesis. Eur J Neurol. 2008 Sep;15(9):991-4. PubMed.
  2. . Clinical-genetic correlations in familial Alzheimer's disease caused by presenilin 1 mutations. J Alzheimers Dis. 2010;19(3):873-84. PubMed.
  3. . 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.
  4. . Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015 May;17(5):405-24. Epub 2015 Mar 5 PubMed.

External Citations

  1. gnomAD v2.1.1

Further Reading

Papers

  1. . Clinical-genetic correlations in familial Alzheimer's disease caused by presenilin 1 mutations. J Alzheimers Dis. 2010;19(3):873-84. PubMed.

Protein Diagram

Primary Papers

  1. . A novel presenilin 1 mutation (V261L) associated with presenile Alzheimer's disease and spastic paraparesis. Eur J Neurol. 2008 Sep;15(9):991-4. PubMed.
  2. . Clinical-genetic correlations in familial Alzheimer's disease caused by presenilin 1 mutations. J Alzheimers Dis. 2010;19(3):873-84. PubMed.

Other mutations at this position

Alzpedia

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