[GM2 gangliosidosis, O variant (Sandhoff disease): suspected diagnosis of a storage disease by ultrasound].

We report on a 3.6 year old boy who suffers from Sandhoff disease. The diagnosis was suspected because of striking ultrasound findings: Parts of the thalamus were more echogenic, the cortical gyri were sharp and accentuated. The CT- and MRI features were similar to the US-findings. The diagnosis was confirmed by demonstrating the typical enzyme deficiency in leucocytes.