MSH2 and pachyonychia congenita: If minor candidate genes are excluded, then data from related studies indicate that 8% of young PC patients have hereditary PC and that a diagnostic panel for hereditary PC should include at least BRCA1, BRCA2, ATM, BRIP1, CHEK2, NBN (c.657del5), HOXB13 (p.G84E), MLH1, MSH2, MSH6, and PMS2 [69].