Biallelic mutations in GBA1 cause the lysosomal storage disorder Gaucher disease, and carriers of GBA1 variants have an increased risk of Parkinson's disease (PD). It is still unknown whether GBA1 variants are also associated with other movement disorders. We present the case of a woman with type 1 Gaucher disease who developed acute dystonia and parkinsonism at 35 years of age during a recombinant enzyme infusion treatment. She developed severe dystonia in all extremities and a bilateral pill-rolling tremor that did not respond to levodopa treatment. Despite the abrupt onset of symptoms, neither Sanger nor whole genome sequencing revealed pathogenic variants in ATP1A3 associated with rapid-onset dystonia-parkinsonism (RDP). Further examination showed hyposmia and presynaptic dopaminergic deficits in [18F]-DOPA PET, which are commonly seen in PD but not in RDP. This case extends the spectrum of movement disorders reported in patients with GBA1 mutations, suggesting an intertwined phenotype.
Objective: aaMutations in the KMT2B gene have been identified in patients previously diagnosed with idiopathic dystonia. Literature on KMT2B-related dystonia is sparse in the Indian and Asian populations.
Methods: aaWe report seven patients with KMT2B-related dystonia studied prospectively from May 2021 to September 2022. Patients underwent deep clinical phenotyping and genetic testing by whole-exome sequencing (WES). A systematic literature search was performed to identify the spectrum of previously published KMT2B-related disorders in the Asian subcontinent.
Results: aaThe seven identified patients with KMT2B-related dystonia had a median age at onset of four years. The majority experienced onset in the lower limbs (n = 5, 71.4%), with generalization at a median duration of 2 years. All patients except one had complex phenotypes manifesting as facial dysmorphism (n = 4), microcephaly (n = 3), developmental delay (n = 3), and short stature (n = 1). Magnetic resonance imaging (MRI) abnormalities were present in four cases. WES revealed novel mutations in the KMT2B gene in all patients except one. Compared to the largest cohort of patients with KMT2B-related disorders, the Asian cohort, comprising 42 patients, had a lower prevalence of female patients, facial dysmorphism, microcephaly, intellectual disability, and MRI abnormalities. Protein-truncating variants were more prevalent than missense variants. While microcephaly and short stature were more common in patients with missense mutations, facial dysmorphism was more common in patients with truncating variants. Deep brain stimulation, performed in 17 patients, had satisfactory outcomes.
Conclusion: aaThis is the largest series of patients with KMT2B-related disorders from India, further expanding the clinico-genotypic spectrum. The extended Asian cohort emphasizes the unique attributes of this part of the world.
Objective: To systematically review and critically evaluate literature on spatiotemporal gait deviations in individuals with premanifest and manifest Huntington's Disease (HD) in comparison with healthy cohorts.
Methods: We conducted a systematic review, guided by the Joanna Briggs Institute's Manual for Evidence Synthesis and pre-registered with the International Prospective Register of Systematic Reviews. Eight electronic databases were searched. Studies comparing spatiotemporal footstep parameters in adults with premanifest and manifest HD to healthy controls were screened, included and critically appraised by independent reviewers. Data on spatiotemporal gait changes and variability were extracted and synthesised. Meta-analysis was performed on gait speed, cadence, stride length and stride length variability measures.
Results: We screened 2,721 studies, identified 1,245 studies and included 25 studies (total 1,088 participants). Sample sizes ranged from 14 to 96. Overall, the quality of the studies was assessed as good, but reporting of confounding factors was often unclear. Meta-analysis found spatiotemporal gait deviations in participants with HD compared to healthy controls, commencing in the premanifest stage. Individuals with premanifest HD walk significantly slower (-0.17 m/s; 95% confidence interval [CI] [-0.22, -0.13]), with reduced cadence (-6.63 steps/min; 95% CI [-10.62, -2.65]) and stride length (-0.09 m; 95% CI [-0.13, -0.05]). Stride length variability was also increased in premanifest cohorts by 2.18% (95% CI [0.69, 3.68]), with these changes exacerbated in participants with manifest disease.
Conclusion: Findings suggest individuals with premanifest and manifest HD display significant spatiotemporal footstep deviations. Clinicians could monitor individuals in the premanifest stage of disease for gait changes to identify the onset of Huntington's symptoms.