CHRNA5 polymorphism and nicotine dependence in patients with cluster headache

Up to 90% of cluster headache (CH) patients have a prolonged history of cigarette smoking prior to the headache onset. A genetic link has been suggested between CH and nicotine addiction and, also, that agents found in cigarette smoke have a direct effect on the hypothalamus, a pivotal area for the pathogenesis of CH . Case-control and genome-wide association studies have reported links between single nucleotide polymorphisms (SNPs) in the alpha-5 nicotinic acetylcholine receptor subunit (CHRNA5) genes and cigarettes smoked per day (CPD). In particular, in vivo studies have demonstrated that 5 subunit is involved in controlling nicotine intake, in mediating nicotine withdrawal symptoms and in affecting anxiety-related behaviour.