4. Genetic Mapping and Linkage
Mapping Genes
11PRACTICE PROBLEM
A geneticist is studying a family with an autosomal dominant disease that has been mapped to chromosome 7. Two DNA markers, A and B, are located on chromosome 7 near the disease locus. The following LOD scores were obtained:
θ = recombination frequency
LOD score
Marker A θ = 0.10 2.1
Marker A θ = 0.20 0.1
Marker B θ = 0.05 1.8
Marker B θ = 0.10 0.4
Based on the LOD scores, which marker is most closely linked to the disease locus?
A geneticist is studying a family with an autosomal dominant disease that has been mapped to chromosome 7. Two DNA markers, A and B, are located on chromosome 7 near the disease locus. The following LOD scores were obtained:
θ = recombination frequency
LOD score
Marker A θ = 0.10 2.1
Marker A θ = 0.20 0.1
Marker B θ = 0.05 1.8
Marker B θ = 0.10 0.4
Based on the LOD scores, which marker is most closely linked to the disease locus?