In humans two single nucleotide polymorphisms (SNPs)occur in about 2,200 nucleotides (~15 million differences between individuals,~3 million charted). Nucleotide (base pair) differences SNPs-single letter(base pair)differences www.hapmap.org Does not account for missing,deleted,repetitive DNA sequences Used to determine common genetic variants that occur in humans Link genetic variants to risk(disease,chemical exposure) OSU rgoIn humans two single nucleotide polymorphisms (SNPs) occur in about 2,200 nucleotides (~15 million differences between individuals, ~3 million charted). SNPs – single letter (base pair) differences Does not account for missing, deleted, repetitive DNA sequences Used to determine common genetic variants that occur in humans Link genetic variants to risk (disease, chemical exposure) www.hapmap.org Nucleotide (base pair) differences