RAPID DETECTION OF LOSS OF HETEROZYGOSITY OF CHROMOSOME 17P BY POLYMERASE CHAIN REACTION-BASED VARIABLE NUMBER OF TANDEM REPEAT ANALYSIS AND DETECTION OF SINGLE-STRAND CONFORMATION POLYMORPHISM OF INTRAGENIC P53 POLYMORPHISMS

Intragenic restriction site polymorphisms in amino acid residue 72 in exon 4 and a Mspl polymorphism in intron 6 of the p53 tumour suppresso r gene can both serve as polymorphic markers. Probe YNZ22 (D17S5) is a highly polymorphic, variable number of tandem repeat (VNTR) marker wh ich maps to chromosome 17p13.1 where the p53 gene is located. Locus sp ecific amplification by polymerase chain reaction (PCR) technique and subsequent non-isotopic single-strand conformation polymorphism analys is of the PCR fragments was used for the detection of loss of heterozy gosity (LOH) of 17p including the p53 gene locus. In combination with a PCR-based method for the analysis of the VNTR locus D17S5 using uniq ue sequences flanking the polymorphic region of YNZ22 we investigated tumour DNA and corresponding constitutional DNA from 69 patients, incl uding 39 patients with gastric cancer, 21 patients with osteosarcomas and 9 patients with Ewing's sarcomas. Using all three methods, 49/69 ( 71%) patients were informative for LOH, which revealed allelic loss in 5/39 (12.8%) gastric cancers, 1/9 (11.1%) Ewing's sarcoma, and 4/20 ( 20%) osteosarcomas.