Fig. 1. Schematic depiction of distribution of the wild-type BLM protein and identified mutant alleles. All currently known mutations are presented in boxes according to convention used in Vihinen et al. (50). Insertions are marked with the "@" sign and deletions with "#" in front of the mutation site. If mutation causes a stop codon it is marked with X and the number of the codon with the newly introduced stop codon. The mutation positions are indicated by vertical lines. Domain organization of BLM protein is shown below mutations.