How Your Genome Works: A Plain-English Guide

Your genome is roughly 3 billion base pairs of DNA encoding about 20,000 genes. SNP arrays from 23andMe or AncestryDNA test around 600,000 pre-selected positions called single nucleotide polymorphisms (SNPs), identified by rsid numbers like rs1801133.

SNP Arrays vs Whole Genome Sequencing

SNP arrays are cost-effective for common variant analysis covering disease risk and pharmacogenomics. Whole genome sequencing reads every base pair and is needed for rare variant discovery, structural variants, and clinical diagnostic confirmation. Clinical databases like ClinVar index both common and rare variants.

What rsids Are

An rsid (Reference SNP cluster ID) is a unique identifier assigned by NCBI dbSNP to a known genetic variant. For example, rs9923231 is the key VKORC1 variant affecting warfarin sensitivity. GenomeNarrator matches your rsids against SNPedia and ClinVar. Learn about pharmacogenomics, GWAS research, or analyze your own genome.