Figure 1. Haplotyping of polymorphic markers on chromosome 15q

The affected mother (II₉) genotyped "CT" for rs1128933 within MAN2C1 and the inferred haplotype of the normal father (II₈) is "CC" based on the paternal haplotype inherited by (III₂₅) and (III₂₇). The "C" allele of rs1128933 is associated with the disease haplotype. II₉ has passed the "C" allele to all of her affected offspring except (III₂₃). III₂₃ is therefore recombinant at the MAN2C1 locus, whereas III₂₁ is not recombinant at this locus. Thus affected parent (II₉) and offspring infer that the disease gene is distal of rs1128933 in the MAN2C1 gene. The disease haplotype inherited from the affected parent is shown by vertical bars.