GM1 gangliosidosis is an autosomal recessive lysosomal storage disease which is characterized by the accumulation of GM1 ganglioside, sphingolipids, glycoprotein bound oligosaccharides and keratan sulphate. Three major clinical forms have been identified depending on the enzyme levels, the timing of onset and severity of the manifestations; infantile form being the most severe. We herein present the clinical features and the histopathological findings of the central nervous system of two cases with type I infantile gangliosidosis; the first one had been diagnosed when she was 8 months old and died at the age of 3; the second one had been diagnosed when he was 10 months old and died at the age of 2. Correlations between clinical features and histopathological findings have been discussed. Postmortem examination of both cases revealed a severe cortical thinning of cerebrum and cerebellum, accompanied by ventricular dilatation. Light microscopic evaluation of cerebral, cerebellar and brainstem sections demonstrated a distortion of normal parenchymal structures and presence of cellular aggregates bearing large, foamy and eosinophilic cytoplasm. Clinical records of the cases revealed a history of delayed mental and motor development, and frequently recurring infection episodes for both cases. Postmortem histopathological examination of such cases enables us to thoroughly identify and describe the multisystemic organ pathologies stemming from gangliosidosis. In this report, we aim to put an emphasis on the specific postmortem neuropathological findings in GM1 gangliosidosis. For a definitive diagnosis, documentation of low ß-galactosidase enzyme levels in leucocytes is a must.

Keywords: GM1 gangliosidosis, autopsy, pathologic findings