TDT Power Calculator

TDT Power Calculator computes statistical power for the Transmission Disequilibrium Test (TDT) in nuclear family-based genetic analyses to evaluate power under diverse family configurations, marker-locus scenarios (including when the marker locus is not a disease susceptibility locus), and allelic heterogeneity.

Key Features:

• Analytical Precision: Employs a novel analytical approach to compute TDT power, with accuracy equivalent or superior to computer simulations as validated against several recent studies.
• Versatility in Family Configurations: Models families with one or multiple children across configurations of affected and unaffected siblings, families ascertained through parental affection status, and mixed samples containing combinations of these family types.
• Marker Locus Flexibility: Handles scenarios where the marker locus is not the disease susceptibility locus, allowing evaluation of marker–disease linkage under indirect association.
• Allelic Heterogeneity Consideration: Accounts for allelic heterogeneity in power calculations to reflect multiple causal variant scenarios.

Scientific Applications:

• Theoretical evaluation: Enables theoreticians to investigate TDT statistical power across complex inheritance models and family-ascertainment schemes.
• Study design for empirical geneticists: Informs empirical geneticists in designing family-based association studies by quantifying power under specific family compositions, marker scenarios, and allelic heterogeneity.

Methodology:

Implements a novel analytical approach to compute TDT power and validates results by comparison to computer simulations and several recent studies.