148Multiple Epiphyseal Dysplasia (MED) (多發性骨骺發育不全症)
149Multiple Pituitary Hormome Deficiency (MPHD) / Anterior Pituitary Hypoplasia (腦下垂體發育不全症)
150Multiple Sclerosis (MS) (多發性硬化症)
151Multiple System Atrophy (MSA) - Pakinsonian Subtype (多重系統退化症-非典型巴金森症)
152Multiple System Atrophy (MSA) - Type C (多重系統退化症-C型)
153Myasthenia Gravis (MG) (重症肌無力症)
154Myhre Syndrome (Myhre綜合症)