GJB2 and Leigh syndrome: Promoters hypermethylated in FAP were in HOXA5, HOXA3, ATP10A, SOX2, HOXA4, CDX2, MIR922, ADAMTSL1, GRHL3, KHDRBS2, FAM102A, CDYL, LITD1, and UGT1A6. Hypermethylated in LS were CUGBP2, GJB2, LOC100130872-SPON2, NEDD4L, FOXP1, THBS1, FILIP1, FRZB, GNG2, and RBM24. Of those, HOXA3 and HOXA5 promoters were hypermethylated also in all LS tumor groups.