| Gene | Description | Location | Gene Omim Number | Disease Omim Number |
| MAN2B1 | MANNOSIDASE, ALPHA, CLASS 2B, MEMBER 1; MAN2B1 | 19cen-q12 | 609458 | 609458 |
| MARVELD2 | MARVEL DOMAIN-CONTAINING PROTEIN 2; MARVELD2 | 5q12.3-q14.1 | 610572 | 610572 |
| MBD5 | METHYL-CpG-BINDING DOMAIN PROTEIN 5; MBD5 | 2q23.1 | 611472 | 611472 |
| MC4R | MELANOCORTIN 4 RECEPTOR; MC4R | 18q22 | 155541 | 155541 |
| MCOLN1 | MUCOLIPIN 1; MCOLN1 | 19p13.3-p13.2 | 605248 | 605248 |
| MECP2 | METHYL-CpG-BINDING PROTEIN 2; MECP2 | Xq28 | 300005 | 300005 |
| MEFV | MEFV INNATE IMMUNITY REGULATOR, PYRIN; MEFV | 16p13 | 608107 | 608107 |
| MEN1 | MULTIPLE ENDOCRINE NEOPLASIA, TYPE I; MEN1 | 11q13 | 131100 | 613733 |
| MERTK | MER TYROSINE KINASE PROTOONCOGENE; MERTK | 2q13 | 604705 | 613862 |
| MPDU1 | MANNOSE-P-DOLICHOL UTILIZATION DEFECT 1; MPDU1 | 17p13.1-p12 | 604041 | 604041 |
| MPZ | MYELIN PROTEIN ZERO; MPZ | 1q22 | 159440 | 159440 |
| MTATP6 | ATP SYNTHASE 6; MTATP6 | NA | 516060 | 256000 |
| MTHFR | 5,10-METHYLENETETRAHYDROFOLATE REDUCTASE; MTHFR | 1p36.3 | 607093 | 607093 |
| MTM1 | MYOTUBULARIN; MTM1 | Xq28 | 300415 | 300415 |
| MTND1 | COMPLEX I, SUBUNIT ND1; MTND1 | NA | 516000 | 535000 |
| MTND4 | COMPLEX I, SUBUNIT ND4; MTND4 | NA | 516003 | 516003 |
| MTTK | TRANSFER RNA, MITOCHONDRIAL, LYSINE; MTTK | NA | 590060 | 545000 |
| MYH7 | MYOSIN, HEAVY CHAIN 7, CARDIAC MUSCLE, BETA; MYH7 | 14q11.2 | 160760 | 160760 |