Genotyping analysis available for patients after hematopoietic cell transplantation for multiple types of lysosomal diseases

Abstract

in filter paper, initially for the detection of heparan sulfamidase (MPS IIIA) and beta-galactosidase (GM1-gangliosidosis, MPS IVB, galactosialidosis) deficiencies. We prepared filter paper samples with dried-leukocytes or dried-fibroblast (DLFP, DFFP) from healthy individuals and from patients with confirmed MPS IIIA or GM1 gangliosidosis by direct transfer of cell homogenates to filter paper discs. Heparan sulfaminidase and beta-galactosidase were tested by incubating samples with specific buffers and substrates. For heparan sulfamidase, a clear discrimination was found between normal controls and MPS IIIA patients both in DLFP and DFFP samples. For beta-galactosidase, distinction between normal controls and GM1-gangliosisdosis patients was evidenced only in DLFP samples so far. Although the method still needs further development, we conclude that assays for these two enzymes could be performed in dried-cell homogenates, and could be an useful tool for LSD identification, especially in areas where liquid blood samples usually need to travel several days to reach the reference laboratory.