Scientific background
In 90% of patients with a choreatic movement disorder of genetic origin, a pathogenic CAG triplet repeat expansion in the HTT gene can be detected. For the remaining 10% with no evidence of a pathological HTT-CAG triplet repeat expansion, a differential diagnosis of Huntington-like disorders, which are clinically difficult or impossible to differentiate, can be clarified by comprehensive gene panel testing. For some of the listed genes, the presence of a repeat expansion is clarified by PCR and subsequent capillary electrophoresis (fragment length analysis).
References
Mencacci et Carecchio 2016, Curr Opin Neurol 29:486 / Hensman Mosset et al. 2014, Neurology 82:292 / Nguyen 2013, MedGen 25:223 / Martino et al. 2013, J Neurol Neurosurg Psychiatry 84:650