Other rare variants mutations in CHCHD2 have been identified in PD patients, but their pathogenicityremains more uncertain [13••,16, 17], and CHCHD2 variants havebeen shown to increase PD risk [18].In total, more than 4100 PD cases and more than 1900 unaffected controls have beenanalyzed to date [13••, 14, 16–25]. The gene discussed is CHCHD2; the disease is Parkinson disease.