Haplin

Haplin performs power and sample size calculations for genetic association analyses in family-based designs, estimating child, parent-of-origin, and maternal effects and supporting SNP and haplotype analyses for autosomal and X-linked variants.

Key Features:

• Flexible Modeling Framework: Uses log-linear and multinomial models to analyze offspring, parent-of-origin, and maternal effects from various child-parent genotype configurations.
• Analytical Power Calculations: Derives power analytically using the asymptotic variance-covariance structure of parameter estimators.
• Simulation-Based Power Calculations: Estimates power via simulation-based techniques implemented in the package.
• Genetic Effects Supported: Supports power calculations for child effects, parent-of-origin effects, maternal effects, and gene-environment interactions.
• Variant Types: Handles single nucleotide polymorphisms (SNPs) and haplotypes on autosomal and X-linked loci.
• Family Configurations: Accommodates case-parent triads, case-mother dyads, and combinations of case-parent triads with unrelated control-parent triads.
• Validation: Computational accuracy of power calculations has been validated by comparison with EMIM using simulations generated by Haplin.

Scientific Applications:

• Study design and planning: Performing sample size and power estimation for family-based genetic epidemiology studies.
• Detection of inheritance effects: Evaluating statistical power to detect child, parent-of-origin, and maternal genetic effects.
• Gene-environment interaction analysis: Assessing power to detect gene-environment interactions in family-based designs.
• X-linked and haplotype analyses: Estimating power for association tests involving X-linked variants and haplotypes.
• Comparative validation: Comparing analytical and simulation-based power estimates against EMIM-derived results for method validation.

Methodology:

Implements log-linear and multinomial modeling; derives analytical power from the asymptotic variance-covariance structure of parameter estimators; provides simulation-based power estimation; validation via comparison with EMIM using Haplin-generated simulations.