"Mutations in the vacuolar protein sorting 13 homolog A (VPS13A) gene, located on chromosome 9q21, have been demonstrated in lineages affected by ChAc 7-9. A variety of mutations occur, with genomic analysis of 11 ChAc families identifying 16 disease-causing mutations in VPS13A 10. "
"Symptom onset occurs in early adulthood at a median of 30 years of age, but ranging from 20th to the 70th decade 2. Approximately one-third of patients initially experience generalised or complex focal seizures, which may precede neurological dysfunction by a decade 1,3. In addition, psychiatric conditions, often depression or obsessive-compulsive symptoms, and parkinsonism may also be presenting features of ChAc 4. The peculiar finding of "feeding dystonia" is pathognomonic of ChAc: upon food touching the tongue, the tongue protrudes and forces the bolus out 5. Chorea typically affects the arms, legs and shoulder and pelvic girdles 2. Movement disorder with choreiform and dystonic components affects gait. Specifically, the presence of "rubber-man appearance", truncal instability and loss of axial tone with sudden, violent flexion and extension spasms, is highly suggestive of ChAc 6."