153Multiple Epiphyseal Dysplasia (MED) (多發性骨骺發育不全症) 
154Multiple Pituitary Hormome Deficiency (MPHD) / Anterior Pituitary Hypoplasia (腦下垂體發育不全症)
155Multiple Sclerosis (MS) (多發性硬化症)
156Multiple System Atrophy (MSA) - Pakinsonian Subtype (多重系統退化症-非典型巴金森症)
157Multiple System Atrophy (MSA) - Type C (多重系統退化症-C型)
158Myasthenia Gravis (MG) (重症肌無力症)  
159Myhre Syndrome (Myhre綜合症)