Mutations

PSEN1 F386S

Overview

Pathogenicity: Alzheimer's Disease : Pathogenic
ACMG/AMP Pathogenicity Criteria: PS3, PM1, PM2, PM5, PP2, PP3
Clinical Phenotype: Alzheimer's Disease
Position: (GRCh38/hg38):Chr14:73217153 T>C
Position: (GRCh37/hg19):Chr14:73683861 T>C
dbSNP ID: rs63749860
Coding/Non-Coding: Coding
DNA Change: Substitution
Expected RNA Consequence: Substitution
Expected Protein Consequence: Missense
Codon Change: TTC to TCC
Reference Isoform: PSEN1 Isoform 1 (467 aa)
Genomic Region: Exon 11

Findings

This mutation was found in a family with five affected members, spanning three generations, having probable or definite AD with onset between 37 and 58 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. In a subsequent study, a French individual with AD age at onset of 36 years was reported (Zarea et al. 2016). This patient developed seizures seven years after disease onset.

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

Neuropathology
Unknown

Biological Effect

A study that examined a range of Aβ peptides produced by human embryonic kidney cells (HEK) expressing this mutant and lacking endogenous PSEN1 and PSEN2 revealed increased Aβ42/Aβ40 and decreased Aβ37/Aβ42, both indicators of reduced Aβ trimming activity (Liu et al., 2022; Apr 2022 news). Of note, in this study, Aβ37/Aβ42 outperformed Aβ42/Aβ40 as a biomarker for distinguishing between control and AD samples. In addition, this variant increased levels of toxic Aβ43 approximately 20-fold compared with wildtype PSEN1.

Consistent with these findings, two other studies reported this variant increasing the Aβ42/Aβ40 ratio (Dumanchin et al., 2016Sun et al., 2017). However, while Sun and colleagues, using purified proteins to test the ability of this mutant to cleave the APP-C99 substrate, reported decreased production of Aβ40, and to a lesser extent Aβ42 (Sun et al., 2017), Dumanchin and coworkers, using transfected HEK cells, reported increased Aβ40 and Aβ42 secretion (Dumanchin et al., 2016). Liu and colleagues found increased Aβ42 levels and decreased Aβ40 levels (Liu et al., 2022).

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). Of note, F386 is adjacent to D385, an aspartate thought to be critical for PSEN1's enzymatic active site (Shea et al., 2016).

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-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: 01 Dec 2022

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References

News Citations

  1. Ratio of Short to Long Aβ Peptides: Better Handle on Alzheimer's than Aβ42/40?

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. . Seizures in dominantly inherited Alzheimer disease. Neurology. 2016 Aug 30;87(9):912-9. Epub 2016 Jul 27 PubMed.
  3. . Identification of the Aβ37/42 peptide ratio in CSF as an improved Aβ biomarker for Alzheimer's disease. Alzheimers Dement. 2022 Mar 12; PubMed.
  4. . Biological effects of four PSEN1 gene mutations causing Alzheimer disease with spastic paraparesis and cotton wool plaques. Hum Mutat. 2006 Oct;27(10):1063. PubMed.
  5. . 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.
  6. . 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.
  7. . Novel presenilin 1 mutation (p.F386I) in a Chinese family with early-onset Alzheimer's disease. Neurobiol Aging. 2017 Feb;50:168.e9-168.e11. Epub 2016 Oct 15 PubMed.

External Citations

  1. gnomAD v2.1.1

Further Reading

Papers

  1. . Familial Alzheimer's disease genes in Japanese. J Neurol Sci. 1998 Sep 18;160(1):76-81. PubMed.

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

Alzpedia

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