BACKGROUND: The very recent availability of fully sequenced individual human 
genomes is a major revolution in biology which is certainly going to provide new 
insights into genetic diseases and genomic rearrangements.
RESULTS: We mapped the insertions, deletions and SNPs (single nucleotide 
polymorphisms) that are present in Craig Venter's genome, more precisely on 
chromosomes 17 to 22, and compared them with the human reference genome hg17. 
Our results show that insertions and deletions are almost absent in L1 and 
generally scarce in L2 isochore families (GC-poor L1+L2 isochores represent 
slightly over half of the human genome), whereas they increase in GC-rich 
isochores, largely paralleling the densities of genes, retroviral integrations 
and Alu sequences. The distributions of insertions/deletions are in striking 
contrast with those of SNPs which exhibit almost the same density across all 
isochore families with, however, a trend for lower concentrations in gene-rich 
regions.
CONCLUSIONS: Our study strongly suggests that the distribution of 
insertions/deletions is due to the structure of chromatin which is mostly open 
in gene-rich, GC-rich isochores, and largely closed in gene-poor, GC-poor 
isochores. The different distributions of insertions/deletions and SNPs are 
clearly related to the two different responsible mechanisms, namely 
recombination and point mutations.