Test Details: Huntington's disease is a late onset autosomal dominant, progressive neuro-degenerative disorder of the central nervous system. Age of onset is variable with most affected individuals manifesting symptoms between 30-50 years. The causative mutation is an expansion of an unstable CAG triplet repeat in the first exon of Huntington (IT15) gene on chromosome 4. The resulting mutant protein - Huntingtin, is concentrated in the basal ganglia and cerebral cortex. A correlation between the length of nucleotide repeats and the onset of the disease, as well anticipation of the disease in high- risk families, has been established. This test involves Triplet primed PCR followed by capillary electrophoresis.