Haplo2D6: A Web-Based Tool for Automated CYP2D6 Haplotype and Phenotype Inference

Motivation Haplo2D6 is a free, browser-based tool that automates the translation of CYP2D6 genotype data into metabolizer phenotypes. Using haplotype reconstruction with the PHASE algorithm, integration of copy number variation estimates, and curated definitions from ClinPGx and PharmVar, Haplo2D6 assigns star alleles, incorporates gene deletions and duplications, calculates activity scores (AS), and predicts phenotype. Results This standardized, high-throughput approach improves reproducibility and reduces interpretation errors compared to manual workflows. It runs in any modern web browser, requires no installation, supports batch processing, and generates downloadable, human-readable results. Availability and implementation Haplo2D6 is accessible at https://bioinfo.dcc.ufmg.br/Haplo2D6/ without registration.