Overview

Pathogenicity: Alzheimer's Disease : Not Classified
ACMG/AMP Pathogenicity Criteria: PP3
Clinical Phenotype: Alzheimer's Disease
Position: (GRCh38/hg38):Chr1:226885663 A>G
Position: (GRCh37/hg19):Chr1:227073364 A>G
dbSNP ID: NA
Coding/Non-Coding: Coding
DNA Change: Substitution
Expected RNA Consequence: Substitution
Expected Protein Consequence: Missense
Codon Change: AAG to AGG
Reference Isoform: PSEN2 Isoform 1 (448 aa)
Genomic Region: Exon 6

Findings

This mutation was found in a large French study reporting 56 new families with autosomal-dominant early onset Alzheimer’s disease. All probands met NINCDS-ADRDA criteria for probable AD and had a family history of disease (Wallon et al., 2012).

The K161R mutation was detected in one individual in a family with three additional affected individuals. Only the genotype of the proband is known, so segregation with disease could not be determined. Age of onset in this family ranged from 61 to 69 years, with a seven- to 16-year clinical disease course.

A subsequent study reported the variant most likely has reduced penetrance, with an allele count of three, and a frequency of 0.0011 percent in the gnomAD variant database (Koriath et al., 2018).

Neuropathology

Unknown.

Biological Effect

The biological effects of this variant are unknown, but its PHRED-scaled CADD score, which integrates diverse information in silico, was above 20, suggesting a deleterious effect (CADD v.1.6, Nov 2021). The mutation was classified as possibly pathogenic according to the algorithm proposed by Guerreiro et al., 2010 (Wallon et al., 2012).

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.

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References

Paper Citations

1. Wallon D, Rousseau S, Rovelet-Lecrux A, Quillard-Muraine M, Guyant-Maréchal L, Martinaud O, Pariente J, Puel M, Rollin-Sillaire A, Pasquier F, Le Ber I, Sarazin M, Croisile B, Boutoleau-Bretonnière C, Thomas-Antérion C, Paquet C, Moreaud O, Gabelle A, Sellal F, Sauvée M, Laquerrière A, Duyckaerts C, Delisle MB, Streichenberger N, Lannes B, Frebourg T, Hannequin D, Campion D. The French series of autosomal dominant early onset Alzheimer's disease cases: mutation spectrum and cerebrospinal fluid biomarkers. J Alzheimers Dis. 2012 Jan 1;30(4):847-56. PubMed.
2. Koriath C, Kenny J, Adamson G, Druyeh R, Taylor W, Beck J, Quinn L, Mok TH, Dimitriadis A, Norsworthy P, Bass N, Carter J, Walker Z, Kipps C, Coulthard E, Polke JM, Bernal-Quiros M, Denning N, Thomas R, Raybould R, Williams J, Mummery CJ, Wild EJ, Houlden H, Tabrizi SJ, Rossor MN, Hummerich H, Warren JD, Rowe JB, Rohrer JD, Schott JM, Fox NC, Collinge J, Mead S. Predictors for a dementia gene mutation based on gene-panel next-generation sequencing of a large dementia referral series. Mol Psychiatry. 2018 Oct 2; PubMed.
3. Guerreiro RJ, Baquero M, Blesa R, Boada M, Brás JM, Bullido MJ, Calado A, Crook R, Ferreira C, Frank A, Gómez-Isla T, Hernández I, Lleó A, Machado A, Martínez-Lage P, Masdeu J, Molina-Porcel L, Molinuevo JL, Pastor P, Pérez-Tur J, Relvas R, Oliveira CR, Ribeiro MH, Rogaeva E, Sa A, Samaranch L, Sánchez-Valle R, Santana I, Tàrraga L, Valdivieso F, Singleton A, Hardy J, Clarimón J. Genetic screening of Alzheimer's disease genes in Iberian and African samples yields novel mutations in presenilins and APP. Neurobiol Aging. 2010 May;31(5):725-31. Epub 2008 Jul 30 PubMed.

Further Reading

No Available Further Reading