Patients with sporadic PC who do not have CDC73 mutations, are likely to have another etiology for their disease and should be offered the opportunity of participating in research studies to elucidate the genetic abnormalities causing this rare disorder (Thakker et al., 2012; Eastell et al., 2014; Wells et al., 2015; Thakker, 2016). Here, CDC73 is linked to pachyonychia congenita.