Loss of heterozygosity in chromosome 4q12-q13 in hepatocellular carcinoma in southern African blacks.

Paired samples of hepatocellular carcinoma and non-tumorous hepatic tissue from 12 southern African blacks were examined for loss of heterozygosity at two loci (D4S409 and D4S392) in chromosome 4q12-q13 (mapping to the same region as the locus for the gene for alpha-fetoprotein). Deoxyribonucleic acid was extracted from carcinoma and non-tumorous tissues and amplified using the polymerase chain reaction. The primers used were based on flanking regions of minisatellite DNA specific for the loci. Products of PCR amplification were separated by denaturing polyacrylamide gel electrophoresis and analysed for allelic losses. At the D4S409 locus one of seven informative samples showed loss of heterozygosity, whereas none of eight informative samples showed loss of heterozygosity at the D4S392 locus. If these findings are considered together with those previously reported in hepatocellular carcinomas from black Africans, the prevalence of loss heterozygosity in chromosome 4q12-q13 in hepatocellular carcinoma in southern African blacks (33 per cent) is the same as that in tumours from Japanese patients. Loss of heterozygosity at chromosome 4q12-q13 is infrequent during hepatocellular carcinogenesis in southern African blacks.