CHIT: an allele-specific method for testing the association between molecular quantitative traits and...

Area of Science:

• Genetics
• Statistical genomics
• Bioinformatics

Background:

• Allele-specific molecular traits from next-generation sequencing are often overlooked in association studies.
• Identifying genotype-phenotype interactions for molecular quantitative traits in complex diseases is challenging due to small effect sizes and sample sizes.

Purpose of the Study:

• To develop a novel statistical method, the Combined Haplotype Interaction Test (CHIT), for detecting associations between molecular quantitative traits and phenotype-genotype interactions.
• To improve the power of genetic association studies by incorporating allele-specific information and interaction effects.

Main Methods:

• CHIT models total and allele-specific read counts in a target region to test for associations.
• It can supplement regular linear interaction regression analyses.
• The method was evaluated using simulations and applied to RNA-seq data for childhood asthma.

Main Results:

• Simulations demonstrated that CHIT maintains non-inflated type I error rates.
• CHIT showed higher statistical power compared to standard interaction quantitative trait locus (QTL) approaches based on linear regression.
• Application to a childhood asthma study in Puerto Ricans indicated CHIT's superior power over standard linear interaction expression QTL analysis.

Conclusions:

• CHIT is a powerful new statistical method for identifying genotype-phenotype interactions in molecular traits.
• The method enhances the ability to detect genetic signals in complex diseases.
• CHIT is available as open-source software for broader research application.