Although methylation analysis is highly relevant to BWS molecular testing, the diagnostic procedures should also include additional analyses since ~30% of cases present other genetic abnormalities.
In the cohort with 84 molecular testing, the FLT3-ITD mutation was found in 22 patients (59%), NPM1 mutations 85 in 17 patients (46%), and a CEBPα mutation in one patient (3%).
Assuming a fairly high accuracy of molecular testing, the performance of the RBG in identifying patients with possible LS was poor, and the AM II criteria falsely identified a large proportion as having possible LS.
These differences can arise from the variable efficiencies of DNA extraction and purification procedures for the subsequent molecular testing, the media used, the preparation of the inoculum for culturing, and the various sensitivities and specificities of the molecular, ELISA and culture tests.
It is possible that the difficulty of collecting samples for molecular testing, the lack of facilities to enable collection of samples for culture in affected areas, and the precise culture requirements of H. ducreyi have notably delayed recognition of this association (14 ).
In this example, as per current practice, before undertaking clinical molecular testing the geneticist could have chosen to send a less-expensive non-genetic lab test named a sterol profile, which if positive would have further increased the physician's a priori suspicion for SLO.
