Six cases from two families (family 1 and family 9) were identified from the Hardie series with a segregating mutation in VPS13A.
The mean age of onset was 25 years (range 8-44). In fact the age of onset was consistent within each family [family 1: 40 years (37-44); family 9: 10 years (8-12)] and therefore the specific type of mutation may have an effect on the age of onset of the condition. The duration of the disease was 23 years (22-24) calculated from age of onset to age of death in two cases from family 1. This may also therefore display interfamily variation.
A movement disorder was the presenting feature in two thirds of cases, and cognitive/psychiatric features in the remainder. Progressive parkinsonism (bradykinesia and rigidity) was present in all but one case, and chorea, tics and dystonia occurred in half the cases. Orolingual dyskinesias were present in one third of cases. Biting of the lip, tongue or cheek was observed in only one out of the six cases with a known VPS13A mutation (although was also present in two of the sporadic cases reported by Hardie et al.). Two thirds of the patients had limitation of upgaze or definite supranuclear gaze palsy. Dysarthria, caused by involuntary choreiform movements and oromandibular and lingual dystonia, was present and progressive in all cases, resulting in severe dysarthria in one third. In addition to the movement disorder, all six cases demonstrated psychiatric features including emotional lability, antisocial behaviour, depression and obsessionality. All six cases demonstrated cognitive impairment. Formal neuropsychometry was performed on three, all of whom showed signs of predominant impaired executive function, suggesting frontal lobe dysfunction . Five out of the six cases were associated with either hyporeflexia or electrophysiological evidence of a peripheral neuropathy. Seizures were present in one case and CK was raised in one case. Neuroimaging demonstrated caudate atrophy in three out of five cases studied. The level of acanthocytes was 10-30% in two thirds of cases while acanthocytes were not detected in the remainder.
Was this article helpful?
This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.