Mutations

PSEN1 I143N

Overview

Pathogenicity: Alzheimer's Disease : Pathogenic
Clinical Phenotype: Alzheimer's Disease
Reference Assembly: GRCh37/hg19
Position: Chr14:73640363 T>A
dbSNP ID: rs63750004
Coding/Non-Coding: Coding
Mutation Type: Point, Missense
Codon Change: ATT to AAT
Reference Isoform: PSEN1 Isoform 1 (467 aa)
Genomic Region: Exon 5

Findings

This mutation was found in a family with five affected members, spanning three generations, having probable or definite AD with onset between 45 and 50 years of age (Raux et al., 2005). The screen included 31 families in whom the entire coding regions of the PSEN1 and PSEN2 genes, as well as exons 16 and 17 of the APP gene, were sequenced from genomic DNA.

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

Neuropathology

Unknown

Biological Effect

The biological effect of this mutation is unknown, but several other mutations linked to AD at this location have been reported to alter Aβ peptide production. Moreover, A cryo-electron microscopy study of the atomic structure of γ-secretase bound to an APP fragment indicates that, in wild-type PSEN1, I143 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).

Last Updated: 02 Aug 2021

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References

News Citations

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

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. . 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. . 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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