ABSTRACT
<p><b>OBJECTIVE</b>To locate the cluster region of loss of heterozygosity (LOH) in children with acute lymphoblastic leukemia (ALL), and explore the new tumor suppressor gene.</p><p><b>METHODS</b>Allelic loss was analyzed by PCR with 15 microsatellite markers mapping on 6q16.3. The LOH was analyzed by bioinformatics. The relationship between LOH and clinical factors was further analyzed.</p><p><b>RESULTS</b>The frequency of LOH at least at one loci on 6q16.3 was 32.7%. The LOH in relapsed patients was higher than those in not relapsed. The higher frequency of LOH was observed in two regions of D6S1709-D6S1028 and D6S2160-D6S1580 at 6q16.3. GRIK2 may be a candidate of tumor suppressor gene. There are 12 ESTs may carry out new anti-oncogene. Patients with 6q LOH had higher WBC counts (P < 0.01), blast cells percentage (P < 0.01), relapse rate (P < 0.05) and chromosomal aberration (P < 0.05).</p><p><b>CONCLUSION</b>D6S1709-D6S1028 and D6S2160-D6S1580 are two regions of minimus deletion on 6q16.3 in which tumor suppressor gene may exist. The LOH on 6q16.3 may be a prognostic index of children with ALL.</p>