Imaging manifestations in infantile GM1 gangliosidosis: a rare lysosomal storage disorder: a paediatric case report.

Mono-sialo-tetra-hexosylganglioside, also known as infantile GM1 gangliosidosis, is an autosomal recessive lysosomal storage disorder caused by a mutation in the GLB1 gene that stops the β-galactosidase enzyme from working. We have discussed a case of infantile GM1 gangliosidosis which presented with abnormal body movements, extensive dermal melanocytosis over back and gluteal region, coarse facial features, and macrocephaly. Radiological features included antero-inferior beaking of second, third, and fourth lumbar vertebrae, bilateral hyperdense thalami on non-contrast CT. On T2-weighted images, there is a persistently high signal intensity of the white matter and subcortical U fibres, which indicates bilateral bulky thalami with T2 hypointense and significantly impaired myelination. Reduced β-galactosidase activity verified the diagnosis.