Detection of germline p53 mutation in patient RUPN 84. SSCP analysis of genomic DNA from the t-AML and from cell line 2L1 showed identical band shift patterns with LOH in the region of p53 exon 8 (arrow, left). Schematic of strategy for PCR amplification andDra I restriction enzyme cleavage and resultant sizes of genomic DNA fragments containing p53 exon 7 and p53 exon 8 are shown below. SSCP analysis of p53 exon 8 in t-AML DNA and DNAs prepared from paraffin-embedded tissues showed the same band shift pattern in the ganglioneuroma, ERMS, and surrounding normal tissues, indicating that the p53 mutation was of germline origin (right). T, tumor tissue; N, normal tissue. There was LOH in the t-AML and the ERMS, but not in the ganglioneuroma. Sequencing of individual genomic subclones from t-AML DNA detected a CGA→TGA nonsense mutation at p53 codon 306 that created a premature termination codon and would foreshorten the predicted protein.