New candidate SNPs for genetic association with Alzheimer's disease: a linkage disequilibrium analysis for the FCGRIIB and PILRA genes

Medwave. 2024 Feb 26;24(1). doi: 10.5867/medwave.2024.01.2754.

Abstract

Background: Two new SNPs have been recently associated to Alzheimer's disease in African American populations: FCGRIIB rs1050501 C/T, and PILRA rs1859788 A/G. The risk of Alzheimer's disease in FCGRIIB C and PILRA A allele carriers is three times higher than in non-carriers. However, the association between these and other single nucleotide polymorphisms (SNPs) has not been assessed.

Methods: Linkage disequilibrium analysis, with r= 0.8 as a threshold value, was used to impute new candidate SNPs, on genomic data from both genes in 26 populations worldwide (n= 2504) from the 1000Genomes database.

Results: Four SNPs (rs13376485, rs3767640, rs3767639 and rs3767641) were linked to rs1050501 and one (rs2405442) to rs1859788 in the whole sample.

Conclusions: Five novel SNPs could be associated with Alzheimer's disease susceptibility and play a causal role, even if none of them are exon variants since their potential roles in the regulation of gene expression.

Antecedentes: Recientemente se han asociado dos nuevos polimorfismos de un solo nucleótido (SNP) a la enfermedad de Alzheimer en poblaciones afroamericanas: FCGRIIB rs1050501 C/T, y PILRA rs1859788 A/G. El riesgo de enfermedad de Alzheimer en los portadores de los alelos FCGRIIB C y PILRA A es tres veces mayor que en los no portadores. Sin embargo, no se ha evaluado la asociación entre estos y otros SNP.

Métodos: Se utilizó el análisis de desequilibrio de ligamiento, con r2= 0,8 como valor umbral, para imputar nuevos SNPs candidatos, sobre datos genómicos de ambos genes en 26 poblaciones de todo el mundo (n= 2504) de la base de datos 1000Genomes.

Resultados: Cuatro SNPs (rs13376485, rs3767640, rs3767639 y rs3767641) se vincularon al rs1050501 y uno (rs2405442) al rs1859788 en toda la muestra.

Conclusiones: Cinco nuevos SNP podrían estar asociados con la susceptibilidad a la enfermedad de Alzheimer y desempeñar un papel causal, aunque ninguno de ellos sea una variante de exón, dado su papel potencial en la regulación de la expresión génica.

Keywords: Alzheimer’s disease; FCGRIIB; PILRA; Single Nucleotide Polymorphisms; genetic association studies; linkage disequilibrium.

MeSH terms

  • Alzheimer Disease* / genetics
  • Genetic Predisposition to Disease
  • Humans
  • Linkage Disequilibrium
  • Membrane Glycoproteins / genetics
  • Polymorphism, Single Nucleotide
  • Receptors, Immunologic / genetics

Substances

  • Membrane Glycoproteins
  • PILRA protein, human
  • Receptors, Immunologic
  • FCGR2B protein, human