Clinical and imaging predictors of late‐onset GM2 gangliosidosis: A scoping review

Abstract

Abstract Objective Late‐onset GM2 gangliosidosis (LOGG) subtypes late‐onset Tay‐Sachs (LOTS) and Sandhoff disease (LOSD) are ultra‐rare neurodegenerative lysosomal storage disorders presenting with weakness, ataxia, and neuropsychiatric symptoms. Previous studies considered LOTS and LOSD clinically indistinguishable; recent studies have challenged this. We performed a scoping review to ascertain whether imaging and clinical features may differentiate these diseases. Methods We examined MEDLINE/non‐MEDLINE databases up to May 2022. Articles reporting brain imaging findings in genetically/enzymatically confirmed LOGG, symptom onset at age ≥ 10 years (or evaluated at least once ≥18 years) were included, yielding 170 LOGG patients (LOTS = 127, LOSD = 43) across 68 papers. We compared LOTS versus LOSD and performed regression analyses. Results were corrected for multiple comparisons. Results Age of onset was lower in LOTS versus LOSD (17.9 ± 8.2 vs. 23.9 ± 14.4 years, p = 0.017), although disease duration was similar (p = 0.34). LOTS more commonly had psychosis/bipolar symptoms (35.0% vs. 9.30%, p = 0.011) but less frequent swallowing problems (4.10% vs. 18.60%, p = 0.041). Cerebellar atrophy was more common in LOTS (89.0%) versus LOSD (60.5%), p < 0.0001, with more severe atrophy in LOTS (p = 0.0005). Brainstem atrophy was documented only in LOTS (14.2%). Independent predictors of LOTS versus LOSD (odds ratio [95% confidence interval]) included the presence of psychosis/bipolar symptoms (4.95 [1.59–19.52], p = 0.011), no swallowing symptoms (0.16 [0.036–0.64], p = 0.011), and cerebellar atrophy (5.81 [2.10–17.08], p = 0.0009). Lower age of onset (0.96 [0.93–1.00], p = 0.075) and tremor (2.50 [0.94–7.43], p = 0.078) were marginally statistically significant but felt relevant to include in the model. Interpretation These data suggest significant differences in symptomatology, disease course, and imaging findings between LOTS and LOSD.