Huntington’s disease is a neurodegenerative genetic disorder on the brain and nervous system. It is a slowly progressive condition with symptoms such as lack of muscle coordination, cognitive decline and behavioural symptoms, it is a unique disease as symptoms often do not show until 35-40 years of age.
It is caused due to a defected gene inherited from the parents, with the gene fault being carried on chromosome 4. Huntington’s is a autosomal dominant disease, meaning it can be inherited if just one parent carries the gene defect, so every child they have will have a 50:50 chance of inheriting the gene.
The gene is non functional due to a set of repeats of the protein HTT .The gene defect leads to specific brain chemical proteins, not being made in the brain as normal. This is thought to lead to damage and death of some neurons in particular regions of the brain (the basal ganglia and cortex).
The fact Huntington’s is a slowly progressive condition means symptoms will gradually develop and worsen as time goes on. People usually live with Huntington’s disease for 10 to 25 years after symptoms first appear, with death usually from an infection such as pneumonia .