Mutation analysis in different liver regions. DNA was extracted from different liver regions and amplified by PCR. PCR products were digested with either Alu I to detect IVS6-1g->t or with Msp I to detect Q279R. For IVS6-1 g->t, the same heterozygous pattern is seen in both the reverted nodule (NT), tumor section (T) and fibroblast DNA (F), showing 3 bands, one at 156-, another at 104- and the last at 75-bp. The control (wt/wt) shows two bands, one at 156- and the other at 75-bp, indicating the absence of IVS6-1g->t (M: molecular weight marker, 100- and 200-bp). For Q279R both the 78- and 58-bp bands are seen in the tumor section (T) and fibroblast DNA (F) indicating an heterozygous genotype while only the 78-bp wild-type band is seen in the control (wt/wt). In the region suspected of reversion (NT), a strong 78-bp wild-type band is seen with a weak 58-bp mutated band (M: molecular weight marker, 100-bp).