Two subsets of A-like var genes differently associated with severe disease. Prior analyses by Warimwe et al.  established that while A-like expression associates with one form of severe disease: impaired consciousness (IC), it does not correlate with another form of severe disease: respiratory distress (RD). Furthermore, while the rosetting phenotype (which correlates with A-like var expression) was found to associates with RD, it was not found to associate with IC. Warimwe et al. concluded that there must be two subsets of A-like var genes that cause severe disease by distinct means: one that causes impaired consciousness by tissue-specific sequestration, and another that causes rosetting, which can lead to respiratory distress (RD). HBs—particularly HBs 204 and 219—improve our ability to distinguish these two classes of severe spectrum var genes.
Rorick et al. BMC Microbiology 2013 13:244 doi:10.1186/1471-2180-13-244