FlexLMM

FlexLMM performs linear mixed model analyses with appropriate permutations for genome-wide association studies when population structure is present.

Key Features:

• Appropriate Permutations in LMMs: FlexLMM performs permutations that account for population structure and covariates, unlike naive permutation approaches.
• Flexible Statistical Model Definition: The pipeline allows flexibility in defining the exact statistical model to be used for the analysis.
• Two-Step Permutation Process: Population structure is first regressed out, and permutations are then performed on the uncorrelated residuals to set a significance threshold.
• Nextflow Implementation: FlexLMM is implemented as a Nextflow pipeline for reproducible and scalable analysis.

Scientific Applications:

• GWAS with Population Structure: FlexLMM enables genome-wide association studies in datasets where population structure would invalidate naive permutation-based significance testing.
• Multi-Parental Crosses: The pipeline is particularly useful for studies involving multi-parental crosses among inbred lines.
• Model Organism Studies: FlexLMM supports genetic studies in model organisms and farm animals and plants where structured populations are common.

Methodology:

FlexLMM uses a two-step process where population structure is first regressed out, followed by permutations performed on the uncorrelated residuals to estimate the null distribution.