CDC73 and pachyonychia congenita: Interestingly, it was reported that CDC73 gene mutations (of which up to 1/3 could be large genomic deletions) [16] may affect subjects with hypercalcemic disorder, regardless of the diagnosis (PHPT, HPT-JT, Familial Isolated Hyperparathyrodism, FIHP, or sporadic PC) [16].