Breath test and genotyping for lactose intolerance in patients with Gaucher ’ s disease treated with miglustat

The iminosugar miglustat, is a treatment for some lysosomal storage disorders that induces gastrointestinal side effects. A retrospective study that evaluates two different tests to assess lactose intolerance was done with the aim to determine whether lactose intolerance is responsible for gastrointestinal symptoms in patients with type 1 Gaucher’s disease. Forty patients with Gaucher’s disease treated or not with miglustat and twenty controls. For that they ingested 50 g lactose, followed by a hydrogen methane breath test. Genotyping and sequencing of a single nucleotide polymorphism (SNP) rs4988235, (CC genotype for lactase non-persistence; TC/TT for lactase persistence) were tested on them. Gastrointestinal symptoms were present in 47.6% (19/40) of patients, 35% (14/40) of whom had a positive hydrogen methane breath test; of these 14 patients, 12 patients were CC-positive and 2 patients were TC-positive. The number of CC alleles was significantly greater in Gaucher’s disease patients compared to controls (62.5% vs. 43.8%). Of the patients who had gastrointestinal symptoms on miglustat treatment, 60.0% had the CC genotype. Conclusion. Hydrogen methane breath test and genotyping for SNPs could be used indistinctly to diagnose lactase deficiency. We have observed that not all gastrointestinal symptoms induced by miglustat in Gaucher’s disease are justified by lactase deficiency.