Does cYP2D6 worldwide genetic variation show high frequency of altered activity variants and no continental structure?
Our study shows that (i) CYP2D6 diversity is far greater within than between populations and groups thereof, (ii) null or low-activity variants occur at high frequencies in various areas of the world, (iii) linkage disequilibrium is lowest in Africa and highest in the Americas. Patterns of variation, within and among populations, are similar to those observed for other autosomal markers (e.g. microsatellites and protein polymorphisms), suggesting that the diversity observed at the CYP2D6 locus reflects the same factors affecting variation at random genome markers.
After prolonged tined-lead testing, we found an infection rate comparable to that reported with the usual short test period. In addition, most patients with bacterial growth on tined leads showed no clinical signs of infection. Thus, prolonged tined-lead testing does not seem to induce clinically relevant infection, warranting randomized trials.