Mutations

PSEN1 Y154C

Overview

Pathogenicity: Alzheimer's Disease : Not Classified
ACMG/AMP Pathogenicity Criteria: PM1, PM2, PM5, PP2, PP3
Clinical Phenotype: Alzheimer's Disease
Reference Assembly: GRCh37/hg19
Position: Chr14:73640396 A>G
dbSNP ID: rs63751292
Coding/Non-Coding: Coding
Mutation Type: Point, Missense
Codon Change: TAT to TGT
Reference Isoform: PSEN1 Isoform 1 (467 aa)
Genomic Region: Exon 5

Findings

The mutation was found in a study of British AD patients with a family history of AD with at least one affected first-degree relative, and an age of onset of less than 61 years (Janssen et al., 2003). The age of onset of the proband was 41 years. Six members of the individual’s family, spanning three generations, were diagnosed with AD. DNA was unavailable from these relatives, however, so co-segregation of the mutation and disease could not be demonstrated. The mutation was absent from 100 healthy, unrelated white control patients.

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

Neuropathology

Unknown.

Biological Effect

The biological effects of this mutation are unknown, but a cryo-electron microscopy study of the atomic structure of γ-secretase bound to an APP fragment, showed that Y154 appears to help stabilize the hybrid β-sheet that forms between PSEN1 and APP in preparation for cleavage (Zhou et al., 2019; Jan 2019).

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 : 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-S

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. Y154C: Variant is in a mutational hot spot and cryo-EM data suggest residue is of functional importance.

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

News Citations

  1. CryoEM γ-Secretase Structures Nail APP, Notch Binding

Paper Citations

  1. . Early onset familial Alzheimer's disease: Mutation frequency in 31 families. Neurology. 2003 Jan 28;60(2):235-9. PubMed.
  2. . Recognition of the amyloid precursor protein by human γ-secretase. Science. 2019 Feb 15;363(6428) Epub 2019 Jan 10 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.

External Citations

  1. gnomAD v2.1.1

Further Reading

No Available Further Reading

Protein Diagram

Primary Papers

  1. . Early onset familial Alzheimer's disease: Mutation frequency in 31 families. Neurology. 2003 Jan 28;60(2):235-9. PubMed.

Other mutations at this position

Alzpedia

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