PP246-MON: Galactose Oxidation Using C in Healthy and Galactosemic Children

Abstract

Rationale: This research aimed to assess if the breath test using 13C-galactose can discriminate healthy children from galactosemic children. Methods: Objectives: (1) Set a cut off point for detecting galactosemia through breath test by constructing a ROC curve. (2) Assess the galactose oxidation ability in healthy children. (3) Assess the galactose oxidation ability in galactosemic children. Methodology: Sampling: 21 healthy children and 7 children with galactosemia with age ranging from 1 to 7 years. Breath test: the breath test of all the children was quantitative for CO2 enrichment in exhaled air before and after oral administration of 7mg/kg of 1-13C-Galactose aqueous solution. Samples were collected at baseline time, 30, 60 and 120min after solution administration. Measurement of the CO2 in the air: molar ratio CO2 and CO2 were quantified by the mass/charge ratio (m/z) of stable isotopes through a mass spectrometer in every air sample. Statistical analysis: ROC curve construction in order to determine the best cutting point of differences in percentage of 1-13C-galactose recovered in CO2 that provides a positive breath test for galactosemia detection. Results: Sick children had some percentage of cumulative 13C in the exhaled air from labeled galactose (CUMPCD) ranging from 0.03% in 30 minutes time to 1.67% in 120 minutes. In contrast, healthy subjects showed a CUMPCD much more expressive, with values ranging from 0.4% in 30 minutes to 5.58% in 120 minutes. Conclusion: This study has shown that there is a great difference in galactose oxidation in children with and without galactosemia, hence the breath test is useful in discriminating children with GALT deficiencies. There is no conflict of interest in this study.