Lysosomal storage disorders (LSDs) are genetically and clinically heterogeneous conditions in which delayed recognition may permit irreversible multisystem injury. Flow-injection analysis tandem mass spectrometry (FIA-MS/MS) of dried blood spots provides a practical first-tier approach for multiplex lysosomal enzyme measurement. We performed a retrospective descriptive analysis of 14,989 valid unique pediatric DBS sample records from 13 geographic categories in Uzbekistan during 2025 after exclusion of technical/non-interpretable entries and duplicate plate identifiers. Of these, 386 samples were laboratory-positive (2.58%). Pompe disease was the most frequent category (141/386, 36.5%), followed by Krabbe disease (105/386, 27.2%), Gaucher disease (76/386, 19.7%), acid sphingomyelinase deficiency/Niemann-Pick disease type A/B (48/386, 12.4%), Fabry disease (10/386, 2.6%), and MPS I based on reduced IDUA activity (6/386, 1.6%). Regional sample denominators were available for all 13 geographic categories; the highest laboratory-positive proportion was observed in Surkhandarya (42/570; 7.37%), followed by Samarkand (87/2,604; 3.34%), Kashkadarya (70/2,152; 3.25%), and Khorezm (44/1,366; 3.22%). Median first-tier activities corresponded to 80.5% (ABG), 79.6% (ASM), 81.6% (GAA), 68.3% (GALC), 53.5% (GLA), and 15.5% (IDUA) of the respective decision limits. These results represent first-tier laboratory-positive signals in a selectively tested sample cohort rather than confirmed diagnoses or population incidence/prevalence. Systematic biochemical and molecular confirmation, patient-level linkage, and analytical batch review are required for definitive interpretation.

Lysosomal storage disorders (LSDs) are genetically and clinically heterogeneous conditions in which delayed recognition may permit irreversible multisystem injury. Flow-injection analysis tandem mass spectrometry (FIA-MS/MS) of dried blood spots (DBS) provides a practical first-tier approach for multiplex lysosomal enzyme measurement. We performed a retrospective descriptive analysis of 14,989 valid unique pediatric DBS sample records from 13 geographic categories in Uzbekistan during 2025 after exclusion of technical/non-interpretable entries and duplicate plate identifiers. Of these, 386 samples were laboratory-positive (2.58%). Pompe disease was the most frequent category (141/386, 36.5%), followed by Krabbe disease (105/386, 27.2%), Gaucher disease (76/386, 19.7%), acid sphingomyelinase deficiency/Niemann-Pick disease type A/B (48/386, 12.4%), Fabry disease (10/386, 2.6%), and mucopolysaccharidosis type I (MPS I) based on reduced α-L-iduronidase (IDUA) activity (6/386, 1.6%). Regional sample denominators were available for all 13 geographic categories; the highest laboratory-positive proportion was observed in Surkhandarya (42/570; 7.37%), followed by Samarkand (87/2604; 3.34%), Kashkadarya (70/2152; 3.25%), and Khorezm (44/1366; 3.22%). Among the laboratory-positive samples, median first-tier activities corresponded to 80.5% for acid β-glucocerebrosidase (ABG), 79.6% for acid sphingomyelinase (ASM), 81.6% for acid α-glucosidase (GAA), 68.3% for galactocerebrosidase (GALC), 53.5% for α-galactosidase A (GLA), and 15.5% for IDUA relative to the respective decision limits. These results represent first-tier laboratory-positive signals in a selectively tested sample cohort rather than confirmed diagnoses or population incidence/prevalence. Systematic biochemical and molecular confirmation, patient-level linkage, and analytical batch review are required for definitive interpretation.