Single nucleotide polymorphisms of the protoporphyrinogen oxidase gene: inter-population heterogeneity of allelic variation

Five single nucleotide polymorphisms (SNPs) in the protoporphyrinogen oxida se gene (PPOX) were used for inter-population comparisons of six South Afri can populations and two non-South African Caucasian populations. Novel poly morphisms identified in the promoter region and exon 11 of the PPOX gene, a s well as three known variants in exon 1 and intron 2, were analysed using single-strand conformation polymorphism (SSCP) and restriction enzyme analy ses. Significant population differences were found for four of the five pol ymorphisms analysed. A C-to-A transition was found at nucleotide position - 1081 and is the first polymorphism to be identified in the 5' promoter regi on of the gene. A novel A-to-C substitution at nucleotide position 3880 in exon 11 was not detected in subjects of European descent. This study repres ents the first inter-population comparison of allelic variation at the PPOX locus. The significant differences observed between populations demonstrat e the importance of population considerations when marker association studi es are performed at this locus. (C) 2001 Academic Press.