Bone marrow transplantation in aspartylglucosaminuria - Histopathological and MRI study

This study comprised two patients with aspartylglucosaminuria (AGU), who we re followed up for 4 and 7 years. The patients underwent allogeneic bone ma rrow transplantation (BMT) at the ages of 2 and 2.6 years. Both patients ha d abnormal speech development and gross motor clumsiness. At the time of th e BMT, they were mentally retarded. We report on follow-up data of these pa tients obtained by MRI, in addition to the histopathological, biochemical a nd clinical investigations. MR images of six non-transplanted patients and seven healthy children served as controls. In the non-transplanted patients , MRI revealed evident delay of myelination in contrast to the two transpla nted patients showing fair or evident grey- vs. white matter differentiatio n on T-2-weighted images. The aspartylglucosaminidase (ACA) activity in blo od leukocytes reached a heterozygous level. Urinary excretion of aspartylgl ucosamine and glycoasparagines slowly decreased but remained about a third of the pre-BMT level 5 years after BMT. Storage lysosomes in electron microscopic investigations were not decreased 6 months after BMT, but after 1.5-2 years, rectal mucosa samples showed a decrease in the storage vacuoles of different cells. Three years after BMT, no cells with storage vacuoles were present. Allogeneic BMT slowly normalises the pathological, biochemical and MRI find ings in patients with AGU.