200 Indians were studied over a period of 15 years, as were more than four groups of the Guaraní people in the Department of Santa Cruz (eastern Bolivia), and no cases of otosclerosis were found in these samples.

Tubal pathology was significantly more common among the younger members of the groups, whilst neurosensory pathology was more common among the older members.

100% from the group was 0 Rh-positive.