Levels of Lyso GL-1 in Gaucher and Lyso GL-3 in Fabry patients from India: Diagnostic aids for these lysosomal storage disorders

• First report of Lyso GL-1 and Lyso GL-3 in Gaucher and Fabry patients from India. • Patients with deficient enzyme activity showed raised level of specific biomarkers. • No specific trend between biomarkers’ levels and pathogenic variants was observed. • Biomarkers: diagnostic aids for Gaucher and Fabry diseases. Lysosomal storage disorders (LSDs) remain a significant cause of morbidity in the Indian population and treatment is largely out of reach for most patients. Although data on enzymatic and molecular diagnosis of Gaucher disease (GD) and Fabry disease (FD) in Indian patients are available, the present study intended to establish the pathogenic levels of Lyso GL-1 and Lyso GL-3 in patients of GD and FD respectively as diagnostic aids. From 2017 to 2019, ninety confirmed Gaucher cases (by enzymatic and molecular analysis) were tested for chitotriosidase (fluorometrically) and Lyso GL-1 (LC-MS/MS) and ten confirmed Fabry cases were analyzed for Lyso GL-3 (LC-MS/MS). Lyso GL-1 (median: 685.5 ng/mL, cut-off: 14) and Lyso GL-3 (median: 75.6 ng/mL, cut-off: 3.5) were found to be elevated in all enzymatically deficient patients of GD and FD respectively, however, no specific trend was observed between the levels of these biomarkers and the pathogenic variant(s) present in the patients of these disorders. This is the first report on Lyso GL-1 and Lyso GL-3 levels in Indian patients of GD and FD respectively. These results will be useful for early diagnosis to improve management of these LSDs.