TSC2 and pachyonychia congenita: Germline mutations in at least 25 different genes have been reported to predispose to PC/PGL/HNPGL or RCC (NF1, RET, MAX, EGLN1, EGLN2, MSH2, KIFIB, SDHAF2,MEN1, BAP1, CDC73, CDKN2B, FLCN, MET, PBRM1, PTEN, TSC1, TSC2, FH, SDHA, SDHB, SDHC, SDHD, TMEM127, and VHL) (6–9, 12–14, 15).