Longitudinal Positron Emission Tomography of Dopamine Synthesis in Subjects with GBA1 Mutations

Mutations in GBA1, the gene mutated in Gaucher disease, are a common genetic risk factor for Parkinson disease, although the penetrance is low. We performed [¹⁸ F]-fluorodopa positron emission tomography studies of 57 homozygous and heterozygous GBA1 mutation carriers (15 with parkinsonism) and 98 controls looking for early indications of dopamine loss using voxelwise analyses to identify group differences in striatal [¹⁸ F]-fluorodopa uptake (K_i ). Forty-eight subjects were followed longitudinally. Cross-sectional and longitudinal comparisons of K_i and K_i change found significant effects of Parkinson disease. However, at baseline and over time, striatal [¹⁸ F]-fluorodopa uptake in mutation carriers without parkinsonism did not significantly differ from controls. ANN NEUROL 2020;87:652-657.