. Mean value of total acid GER index in a subgroup of children with primary GER constituted x = 11.13 +/- 1.45 and was not statistically significant in comparison with mean value x = 12.13 +/- 1.30 of a parameter measured in a subgroup of children with secondary GER. The most common clinical manifestation was apnea and it was of identical prevalence in both study subgroups