Figure 1

Hypothetical example of detection of genotyping errors through Genome Polymorphism Scans. Shown are two multiallelic polymorphisms 5 cM apart from a Scan, A and B, which flank a disease locus (indicated by the arrow in the granddaughter) with a rare disease allele D and normal allele N. Unambiguous haplotypes are determined by inspection in both mother and granddaughter. Barring a highly improbable event, the granddaughter will carry the D allele on the haplotype inherited from her mother. Any test result in the granddaughter at the disease locus which does not yield a D, N genotype is very likely incorrect and should be repeated.