Allelotype analysis in relapsed childhood XXXX .

@entity1 @entity2214 @entity981 @entity986 @entity9604
We performed for the first time the allelotype of relapsed childhood @entity981 ( @entity981 ). A total of 38 cases were screened for loss of heterozygosity (LOH) using 71 markers. In all, 26 (68%) @entity1 showed LOH on at least one chromosomal arm, indicating that LOH is a frequent event at relapse. The most frequent loss was found on chromosomal arm 9p at the @entity986 / @entity986 locus (39%). LOH at the @entity9604 gene locus on chromosomal arm 12p also occurred often (25%). Frequent loss was observed on chromosome arms 4q (20%), 6q (21%), and 17q (20%). Sequential analysis (i.e. samples obtained from both initial diagnosis and relapse) shows that some @entity1 (63%) have the identical LOH status at both phases, suggesting the presence of the same clone. Other samples (37%) showed distinct LOH alterations, indicating @entity2214 at relapse. Despite the heterogeneous and complex changes, some shared LOH loci occurred in these matched samples, suggesting that many of the same tumor-suppressor genes are aberrant at both phases. In summary, novel tumor-suppressor genes on chromosome arms 4q, 6q, and 17q, as well as the @entity986 and @entity9604 genes, have an important role in the relapse of @entity981 .
