SNP example
..GAATCTTATGCTATACATAATTATATACTAATCGGGTATTGTTCTTAT..
..CTTAGAATACGATATGTATTAATATATGATTAGCCCATAACAAGAATA..
..GAATCTTATGCTATACATAATTATATACTAATAGGGTATTGTTCTTAT..
..CTTAGAATACGATATGTATTAATATATGATTATCCCATAACAAGAATA..
These may be detected by sequencing or by RFLPs or SSCP.