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Updated: Dec 30, 2025

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Three Differential Expression Analysis Methods for RNA Sequencing: limma, EdgeR, DESeq2
Published on: September 18, 2021
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qtQDA: quantile transformed quadratic discriminant analysis for high-dimensional RNA-seq data.
Necla Koçhan1, G Yazgi Tutuncu1, Gordon K Smyth2,3
1Department of Mathematics, Izmir University of Economics, Izmir, Turkey.
Peerj
|January 25, 2020
Summary
A new gene expression classification method, qtQDA, accurately analyzes RNA-seq data by modeling gene dependencies. This approach offers improved performance for modern medicine applications.
Area of Science:
- Genomics
- Bioinformatics
- Computational Biology
Background:
- Gene expression data from RNA-sequencing (RNA-seq) is crucial for modern medicine.
- Existing classification methods may not fully account for the inherent dependencies between gene measurements.
Purpose of the Study:
- To introduce a novel classification method for RNA-seq data.
- To address the challenge of dependent measurements in gene expression data.
Main Methods:
- Proposed a new statistical model for gene expression data.
- Data is marginally negative binomial but dependent.
- Employed a quantile transformation (qt) followed by Gaussian quadratic discriminant analysis (QDA) with regularized covariance matrices, termed qtQDA.
Main Results:
- qtQDA demonstrated excellent performance on real-world datasets.
- The method showed advantages over several existing classification approaches.
- An R package for qtQDA is publicly available.
Conclusions:
- qtQDA is a powerful new tool for gene expression classification.
- The method effectively incorporates gene dependencies, improving classification accuracy.
- This approach has significant potential for applications in precision medicine.
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