Abnormal DaTscan in GM1‐Gangliosidosis Type III Manifesting with Dystonia‐Parkinsonism

Abstract

GM1-gangliosidosis is a rare lysosomal storage disorder caused by biallelic GLB1 variants leading to β-galactosidase deficiency. 1,2 Level of residual enzymatic activity at least partly explains its phenotypic heterogeneity, including variability in age at symptom onset, clinical severity, and progression rate. 1-3 Three phenotypes are described, including infantile-onset (type I) and late infantile/juvenile-onset (type II) forms, which are lethal in early childhood, and late-onset form (type III), which manifests between late childhood and the third decade. 1,2 GM1-gangliosidosis type III, whose milder phenotype usually permits survival into adulthood, 2 manifests as a complex syndrome featuring skeletal dysplasia, corneal opacities, progressive generalized dystonia with prominent oromandibular and bulbar involvement, akinetic-rigid parkinsonism, and cognitive decline in later stages. 1 Despite neuropathology demonstrates selective deposition of glycosphingolipids (ie the substrate of β-galactosidase) in the basal ganglia leading to prominent striatal neuronal loss, 4,5 in vivo evidence suggesting nigrostriatal degeneration is extremely scant. 6 We report abnormal presynaptic dopaminergic imaging and long-term follow-up of a case of GM1-gangliosidosis type III whose genotype and biochemical analysis were previously reported. 7

I123‐FP‐CIT (DaTSCAN) SPECT beyond the Most Common Causes of Parkinsonism: A Systematic Review

“…Marangi et al described a reduced DaTSCAN uptake in the basal ganglia in a patient affected by this disorder, suggesting a presynaptic dopaminergic deficiency possibly related to lesion topography 51 . The reduced DaTSCAN uptake in both the putamen and the striatum reported by Koya Kutti et al further confirmed the presence of presynaptic dopaminergic dysfunction associated with this disorder 52 …”

“…51 The reduced DaTSCAN uptake in both the putamen and the striatum reported by Koya Kutti et al further confirmed the presence of presynaptic dopaminergic dysfunction associated with this disorder. 52…”