Related Experiment Video
Updated: Mar 21, 2026

Intrastriatal Injection of Autologous Blood or Clostridial Collagenase as Murine Models of Intracerebral Hemorrhage
Published on: July 3, 2014
The APOE paradox: divergent genetic influences on hemorrhagic stroke risk-A meta-analysis
Manabesh Nath1, Astha Rai2, Shubham Misra3
1Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Background:
Apolipoprotein E (APOE) regulates lipid metabolism and neuronal repair, yet its alleles show contrasting effects on hemorrhagic stroke (HS) risk. While some variants increase susceptibility, others appear protective, leading to inconsistent findings. This meta-analysis systematically evaluates the APOE-HS association to clarify its role in stroke pathophysiology.
Methods:
A comprehensive literature search was conducted across multiple databases up to January 31, 2025, using the keywords: ("Apolipoprotein E" OR "APOE" OR "APOE genotype") AND ("Single Nucleotide Polymorphisms" OR "SNP") AND ("Hemorrhagic stroke" OR "HS" OR "Intracerebral Hemorrhage" OR "ICH"). The APOE ε3/ε3 genotype served as the reference genotype in all studies, and only those studies with ε3/ε3 genotype were included in the analysis. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, and statistical analyses were performed using STATA version 13.0 (StataCorp LLC, College Station, Texas, United States).
Results:
A total of 24 studies comprising 8,269 HS patients and 26,321 controls were included. Meta-analysis revealed a significant association of APOE ε2/ε2 (OR = 1.93, 95% CI = 1.32-2.81), ε4/ε4 (OR = 1.60, 95% CI = 1.21-2.13), ε2/ε4 (OR = 1.81, 95% CI = 1.34-2.44), ε2 (OR = 1.23, 95% CI = 1.12-1.35), and ε4 (OR = 1.31, 95% CI = 1.14-1.51) with an increased risk of HS.
Conclusion:
Our findings suggest that APOE ε2/ε2, ε2/ε4, ε2, and ε4/ε4 genotypes and the ε4 allele are associated with an elevated risk of HS. These results highlight the potential role of APOE genotypes in HS susceptibility and warrant further investigation.
Related Concept Videos
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Genome-wide Association Studies-GWAS
GWAS does not require the identification of the target gene involved in...
Regulation of Stroke Volume
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...
Human Genetics
The complex relationship between genetics and psychology is observable through common biological components such...
Pharmacogenomics: Identification of New Drug Targets
Principles of Pharmacogenetics: Types of Genetic Variants

