Novel restriction fragment length polymorphisms in the cellular oncogene SEA.
The human homologue of the SEA oncogene has been mapped recently to chromosome band 11q13. While studying the possible involvement of this gene in the variant translocation t(9;22;11) (q34;q11;q13) in a case of chronic myelogenous leukemia, we identified novel polymorphisms for XbaI and SacI restriction enzyme sites in the SEA gene. Frequency of the polymorphic alleles was studied in 100 samples from healthy controls, 94 samples from patients with non-Hodgkin's lymphoma, 25 samples from patients with benign lymphadenopathy, and 38 samples from patients with chronic myelogenous leukemia. XbaI digestion showed a three-allele polymorphism with two frequent alleles A (8.0 kb) and B (9.2 kb) and a rare allele (5.8 kb). After SacI digestion the probe identified two primary genotypes. Genotype I showed two hybridizable DNA fragments, one each of 6.6 and 3.5 kb. In genotype II the 3.5 kb fragment was absent, instead two smaller fragments, one each of 1.9 kb and 1.6 kb were present. The 6.6 kb fragment (allele AA) had three polymorphic sites generating 6.2 kb fragment (allele BB), 7.4 kb fragment (allele CC), and 7.8 kb fragment (allele DD). Frequencies of the two genotypes and the four alleles followed Mendelian proportions in all the samples studied. Furthermore, this study shows the importance of restriction map analysis of DNA in the vicinity of the probe of an oncogene to distinguish natural polymorphisms from the disease-related rearrangements in the gene.
Koduru
P R
PR
Department of Laboratories, North Shore University Hospital, Manhasset, New York.
Goh
J C
JC
Broome
J D
JD
D004247:DNA / Q000032:analysis* / Q000097:blood; D015252:Deoxyribonucleases, Type II Site-Specific; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length; D011519:Proto-Oncogenes / Q000235:genetics*; D015183:Restriction Mapping; D014407:Tumor Cells, Cultured
D004247:DNA; C024408:endodeoxyribonuclease SacI; C025580:endodeoxyribonuclease XBAI; D015252:Deoxyribonucleases, Type II Site-Specific