The exact mechanism of Huntington's disease is known.
Expansion of CAG -LRB- cytosine-adenine-guanine -RRB- triplet repeats in the gene coding for the Huntingtin protein results in an abnormal protein , which gradually damages cells in the brain , through mechanisms that are not fully understood .	gene	gene	Huntingtin	Huntingtin	cytosine	cytosine	adenine	adenine	guanine	guanine
