Can CANVAS due to biallelic expansions present with pure ataxia?

Background: Biallelic expansion of AAGGG in the replication factor complex subunit 1 () was identified as a major cause of cerebellar ataxia, neuropathy (sensory ganglionopathy, or SG) and vestibular areflexia syndrome (CANVAS). We wanted to clarify if expansions can present with pure ataxia and if such expansions could be responsible for some cases where an alternative diagnosis had been made.

Methods: We identified patients with a combination of ataxia and SG and no other cause found, patients where an alternative diagnosis had been made, and patients with pure ataxia.

Value of systematic genetic screening of patients with amyotrophic lateral sclerosis.

Objective: The clinical utility of routine genetic sequencing in amyotrophic lateral sclerosis (ALS) is uncertain. Our aim was to determine whether routine targeted sequencing of 44 ALS-relevant genes would have a significant impact on disease subclassification and clinical care.

Methods: We performed targeted sequencing of a 44-gene panel in a prospective case series of 100 patients with ALS recruited consecutively from the Sheffield Motor Neuron Disorders Clinic, UK.

Simultaneous ALS and SCA2 associated with an intermediate-length CAG-repeat expansion.

Spinocerebellar ataxia type 2 (SCA2) and amyotrophic lateral sclerosis (ALS) share a common molecular basis: both are associated with CAG-repeat expansion of and TDP-43-positive neuronal cytoplasmic inclusions. To date, the two disorders are viewed as clinically distinct with ALS resulting from 30-33 CAG-repeats and SCA2 from >34 CAG-repeats. We describe a 67-year old with a 32 CAG-repeat expansion of who presented with simultaneous symptoms of ALS and SCA2.

Novel genotype-phenotype and MRI correlations in a large cohort of patients with mutations.

Objective: To clinically, genetically, and radiologically characterize a large cohort of patients.

Methods: We used data from next-generation sequencing panels for ataxias and hereditary spastic paraplegia to identify a characteristic phenotype that helped direct genetic testing for variations in . We analyzed MRI.