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