Mutations

PSEN1 I213F

Overview

Pathogenicity: Alzheimer's Disease : Pathogenic
ACMG/AMP Pathogenicity Criteria: PS3, PM1, PM2, PM5, PP2, PP3
Clinical Phenotype: Alzheimer's Disease
Reference Assembly: GRCh37/hg19
Position: Chr14:73659440 A>T
dbSNP ID: rs63750861
Coding/Non-Coding: Coding
DNA Change: Substitution
Expected RNA Consequence: Substitution
Expected Protein Consequence: Missense
Codon Change: ATT to TTT
Reference Isoform: PSEN1 Isoform 1 (467 aa)
Genomic Region: Exon 7

Findings

This mutation was first identified in a Polish man with a family history of probable AD, including four affected family members spanning two generations (Żekanowski et al, 2003). The proband’s first symptom, at age 33, was memory impairment, followed by mood alterations, including anxiety, and disorientation in time and space. The man also developed rigidity and bradykinesia. Similarly, disease onset in his affected relatives was before 35 years, and they all died before the age of 40 with probable AD.

Another Polish carrier, a man diagnosed with early onset AD in his 30s, was subsequently identified (Łabuz-Roszak et al., 2021). In this case, the patient was hospitalized with cognitive dysfunction, speech disorders, and features of Parkinson's extrapyramidal syndrome, all of which had been progressing for approximately 15 months.

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

Neuropathology
Neuropathological data are unavailable, but one of the carriers had Aβ and tau levels in cerebrospinal fluid typical of AD, and brain MRI revealed cortical and subcortical atrophy, especially in the patieral and temporal lobes (Łabuz-Roszak et al., 2021).

Biological Effect
Human embryonic kidney cells transfected with an APP construct carrying the Swedish mutation and PSEN1 I213F, secreted more Aβ40 and Aβ42 than cells transfected with wild-type PSEN1, and the Aβ42/Aβ40 ratio was elevated nearly three-fold (Bialopiotrowicz et al., 2012). ConSeq program analysis suggested codon 213 is highly conserved (Żekanowski et al, 2003). Moreover, a cryo-electron microscopy study of the atomic structure of γ-secretase bound to an APP fragment indicates this residue is apposed to the APP transmembrane helix, with its side-chain reaching towards the interior of the substrate-binding pore (Zhou et al., 2019; Jan 2019 news).

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.

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. I213F: Variant is in a mutational hot spot and cryo-EM data suggest residue is of functional importance.

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

News Citations

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

Paper Citations

  1. . Mutations in presenilin 1, presenilin 2 and amyloid precursor protein genes in patients with early-onset Alzheimer's disease in Poland. Exp Neurol. 2003 Dec;184(2):991-6. PubMed.
  2. . Early onset Alzheimer's disease - a case study. Psychiatr Pol. 2021 Apr 30;55(2):323-330. PubMed.
  3. . Highly Pathogenic Alzheimer's Disease Presenilin 1 P117R Mutation Causes a specific Increase in p53 and p21 Protein Levels and Cell Cycle Dysregulation in Human Lymphocytes. J Alzheimers Dis. 2012 Jan 1;32(2):397-415. PubMed.
  4. . Recognition of the amyloid precursor protein by human γ-secretase. Science. 2019 Feb 15;363(6428) Epub 2019 Jan 10 PubMed.
  5. . 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

Papers

  1. . Familial Alzheimer's Disease Lymphocytes Respond Differently Than Sporadic Cells to Oxidative Stress: Upregulated p53-p21 Signaling Linked with Presenilin 1 Mutants. Mol Neurobiol. 2016 Sep 19; PubMed.

Protein Diagram

Primary Papers

  1. . Mutations in presenilin 1, presenilin 2 and amyloid precursor protein genes in patients with early-onset Alzheimer's disease in Poland. Exp Neurol. 2003 Dec;184(2):991-6. PubMed.

Other mutations at this position

Alzpedia

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