HD is a genetic neurodegenerative disease due to pathological expansion of the triplet cytosine-adenine-guanine (CAG) repeat in the Huntingtin gene in chromosome 4, which results in an excessively long polyglutamine stretch in protein Huntingtin and eventually causes loss of GABAergic neurons in striatum [4]. The gene discussed is HTT; the disease is Genetic neurodegenerative disease.