LOT

LOT performs linkage analysis of ordinal traits in pedigree datasets to model inheritance patterns and test for linkage between genetic markers and ordinal phenotypes.

Key Features:

• Latent-variable proportional-odds logistic model: Models ordinal trait outcomes using a latent-variable extension of the proportional-odds logistic framework.
• Likelihood-ratio test for linkage: Evaluates evidence of linkage between genetic markers and ordinal traits using likelihood-ratio testing.
• Pedigree-based analysis: Operates on pedigree datasets to relate familial structure to trait distributions.
• Ordinal-trait focus: Specifically targets traits measured on ordinal scales rather than binary or continuous measures.
• Inheritance-pattern modeling: Relates latent genetic effects to the distribution of ordinal traits within families to capture underlying genetic architecture.

Scientific Applications:

• Linkage analysis of ordinal phenotypes: Detects linkage signals for phenotypes recorded on ordered categorical scales within family data.
• Behavioral disorder genetics: Supports genetic investigations of behavioral disorders that are rated on ordinal scales.
• Complex disease studies: Facilitates analysis of complex human conditions where traits are not easily quantifiable but exhibit ordered categories.
• Family-based genetic research: Enables studies of transmission of ordinal traits across generations in pedigree-based designs.

Methodology:

Implements a latent-variable proportional-odds logistic model to relate latent genetic effects to the distribution of ordinal traits within families and applies likelihood-ratio tests to assess linkage between genetic markers and ordinal traits.