ANNOVAR

ANNOVAR annotates genetic variants from high-throughput sequencing data to report functional consequences and prioritize candidate variants for research and clinical interpretation.

Key Features:

• Functional Annotation: Annotates single nucleotide variants (SNVs) and insertions/deletions (indels) with gene-based and region-based consequences.
• Conservation Analysis: Identifies variants in conserved regions across species to assess evolutionary conservation.
• Functional Importance Scores: Computes predicted impact scores using SIFT and PolyPhen.
• Cytogenetic Band Inference: Infers cytogenetic bands to provide chromosomal context for variants.
• Database Integration: Integrates annotation datasets from the UCSC Genome Browser and accepts datasets in Generic Feature Format version 3 (GFF3).
• Public Database Reporting: Retrieves allele frequencies from public databases such as the 1000 Genomes Project and dbSNP.
• Variants Reduction Protocol: Implements a variants reduction protocol to exclude variants unlikely to be causal and narrow candidate genes, demonstrated in studies of rare disorders such as Miller syndrome.

Scientific Applications:

• Research: Supports annotation of newly sequenced genomes for human and nonhuman species in large-scale studies.
• Clinical Genomics: Aids interpretation of personal genome data by reporting candidate deleterious variants for clinical assessment.
• Mendelian Disease Analysis: Prioritizes candidate genes and variants for Mendelian disease studies and causal mutation discovery.

Methodology:

Performs gene-based and region-based annotation, identifies conserved regions, computes SIFT and PolyPhen scores, infers cytogenetic bands, integrates UCSC Genome Browser datasets and GFF3 inputs, retrieves allele frequencies from the 1000 Genomes Project and dbSNP, and applies a variants reduction protocol; reported example runtimes include gene-based annotation in ~4 minutes and variants reduction on 4.7 million variants in ~15 minutes.