Guest post by Rachel Harding, postdoctoral fellow at the Structural Genomics Consortium, University of Toronto, Canada

{credit}Rachel Harding{/credit}

Huntington’s disease (HD) is a fatal neurodegenerative disorder caused by a mutation in the huntingtin gene¹. The progressive break down of brain neuronal cells in HD patients leads to deteriorating mental and physical abilities over a 10-20 year period prior to death, the symptoms often described as having Parkinson’s disease, Alzheimer’s disease and amyotrophic lateral sclerosis (ALS) simultaneously². At the start of the huntingtin gene there is a CAG trinucleotide repeat region that encodes a stretch of poly-glutamine residues in the amino-terminus of the encoded protein. This repeat tract is expanded in HD patients. The repeat length of this region correlates with the age of symptom onset³. Affecting approximately 1 in 10,000 of the population⁴, rare juvenile forms of the disease exist in patients with the longest CAG expansions, although adult-onset HD patients typically have between 40-50 CAG repeats with symptom onset beginning between the ages of 35-50. Continue reading →