Evaluation of genetic and environmental effects using GEE and APM methods

Area of Science:

• Genetics
• Biostatistics
• Epidemiology

Background:

• Genetic and environmental factors influence complex diseases.
• Accurate statistical methods are crucial for identifying disease-associated genes.
• Familial correlation presents a challenge in genetic association studies.

Purpose of the Study:

• To evaluate candidate genes and an environmental factor for association with quantitative traits and disease affection status.
• To compare the performance of generalized estimating equations (GEE) and affected-pedigree-member (APM) methods in genetic analysis.

Main Methods:

• Generalized estimating equations (GEE) modelling was employed to account for familial correlation in regression analyses.
• The affected-pedigree-member (APM) method was utilized to detect chromosomal regions and gene linkage with disease status.
• Candidate genes (C5/MG1, C2/MG2) and an environmental factor were assessed against quantitative traits (Q1, Q2) and disease affection status (DIS).

Main Results:

• GEE identified C5 (MG1) as significantly associated with quantitative trait Q1 and disease affection status DIS.
• The APM method provided only suggestive evidence for C5 (MG1) in relation to Q1 and DIS.
• GEE indicated C2 (MG2) was important for Q2, marginally for Q1, and not significant for DIS.

Conclusions:

• GEE is a robust method for identifying genetic associations in the presence of familial correlation.
• C5 (MG1) is a potential genetic contributor to quantitative trait Q1 and disease affection status DIS.
• C2 (MG2) shows a significant association with Q2, warranting further investigation.