Juvenile HD (JHD) is the result of genetic anticipation that occurs due to instability of CAG expanded alleles (HTT gene) when passed to the next generation, resulting in earlier onset of clinical manifestations in successive generations.
The aim of this study was to report a Brazilian case of JHD with paternal transmission.
We evaluated a patient with JHD with chorea, cervical dystonia and aggressiveness. The Unified Huntington' Disease Rating Scale (UHDRS) was applied. The size of CAG allele was double-checked in two laboratories.
We report a patient with paternally inherited JHD caused by a large expansion (74 CAG). The patient was prescribed olanzapine 2.5 mg q.d., oxcarbazepine 300 mg bid and underwent botulinum toxin treatment, with partial improvement of aggressiveness and chorea and partial resolution of torticollis. The MRI revealed bilateral caudate and putamen atrophy. JHD is rarer than adulthood HD, with an average prevalence rate of 5%. UHDRS has limited efficacy in evaluating JHD patients independence and functional capacity, as it was originally developed for adult subjects. There is currently no specific scale for JHD patients.