Genetic Variation in the Ontario Neurodegenerative Disease Research Initiative

Area of Science:

• Neurogenetics
• Neurodegenerative Diseases
• Human Genetics

Background:

• Apolipoprotein E (APOE) E4 is a primary genetic risk factor for Alzheimer's disease (AD).
• Investigating APOE E4's role in other neurodegenerative diseases is crucial.
• Microtubule-associated protein tau (MAPT) haplotypes are also explored as potential genetic biomarkers.

Purpose of the Study:

• To determine if APOE E4 or MAPT H1 haplotype are associated with five neurodegenerative diseases.
• To analyze associations with Alzheimer's disease (AD), mild cognitive impairment (MCI), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), Parkinson's disease, and vascular cognitive impairment.

Main Methods:

• Genotyping of APOE alleles and MAPT haplotypes in participants from the Ontario Neurodegenerative Disease Research Initiative.
• Logistic regression analyses were used to identify associations between genetic factors and disease phenotypes.

Main Results:

• The APOE E4 allele showed a dose-dependent association with increased AD and MCI presentation.
• The APOE E2 allele was associated with a decreased risk of AD and MCI.
• No significant associations were found between MAPT haplotypes and the broader neurodegenerative disease cohorts, except for an association between MAPT H1 and progressive supranuclear palsy within the FTD subtype.

Conclusions:

• This study provides comprehensive analysis of APOE and MAPT associations across multiple neurodegenerative diseases.
• APOE E4's role appears specific to AD and MCI, while MAPT H1 shows a specific link to PSP within FTD.