30Arthrogryposis Multiplex Congenita (AMC) (先天性多發性關節攣縮症)
31ATAD3A Syndrome (Genetic Disorder)
32ATR-X Thalassemia Syndrome (ATRX) (α地中海贫血X-連鎖智力障碍症)
33Atypical Hemolytic Uremic Syndrome (aHUS) (非典型溶血性尿毒症)
34Autoimmune Insulin Syndrome (胰島素自身免疫綜合症)
35Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) (Charlevoix-Saguenay型隐性痙攣性共濟失調症)