Multivariate analysis revealed significant associations between post-traumatic headache with cluster headache phenotype (PTH-CH) and family history of CH (OR: 3.32, 95% CI: 1.31–8.63), in the chronic form (OR: 3.29, 95% CI: 1.70–6.49). The gene discussed is PTH; the disease is cyclic hematopoiesis.