Detection of LOH on chromosome 12p by microsatellite marker mapping.

Allotypes at informative (heterozygous) markers are shown for each patient at presentation (Pr) and relapse (Rel). (A) Patient 1 (late relapse) retains heterozygosity at markers D12S94 and D12S62 but shows LOH (markers D12S1697, D12S89, D12S358, and D12S320) at presentation but not at relapse. (B) Patient 2 (late relapse) shows LOH of marker D12S77 at relapse but not at presentation and LOH of marker D12S269 at presentation but not at relapse. (C) Patient 3 (early relapse) cells at presentation were FACS sorted (S) and show heterozygosity at markers D12S77 and D12S269, as does relapse DNA. Sorted cells at presentation show microsatellite instability in D12S1697 with the appearance of an extra band not present in remission (Rm) and further show LOH at relapse. Marker D12S89 is heterozygous in remission but shows LOH at presentation (S).