FIGURE 4.

Prevalence of laterality defects per predicted ciliary ultrastructure and country. The prevalence of laterality defects is 42% in the total study cohort (n=519 individuals with laterality defects). There is a significant difference between the groups stratified according to the predicted effect of genetic variants on ciliary ultrastructure. In the group of 894 individuals with genetic variants associated with pathognomonic ciliary ultrastructure defects detectable by transmission electron microscopy, 51% of individuals (n=457) have laterality defects. In contrast, in the group of individuals with genetic variants not associated with defective ciliary ultrastructure hallmark, only 18% of individuals (n=55) have laterality defects (p<0.0001). The prevalence of laterality defects varies widely among the participating countries and ranges from 28% to 69%. It is lowest in Turkey (28%), the Netherlands (31%), Germany (37%), Spain (39%) and Israel (40%).