A in Rare Diseases
- Aagenaes syndrome
- Aarskog syndrome
- Aase Smith syndrome
- Aase syndrome
- ABCD syndrome
- Abderhalden-Kaufmann-Lignac syndrome
- Abdominal aortic aneurysm
- Abdominal chemodectomas with cutaneous angiolipomas
- Abdominal cystic lymphangioma
- Abdominal obesity metabolic syndrome
- Aberrant subclavian artery
- Abetalipoproteinemia
- Abidi X-linked mental retardation syndrome
- Ablepharon macrostomia syndrome
- Abrikosov's tumor
- Abruzzo Erickson syndrome
- Absence defect of limbs- scalp- and skull
- Absence of Gluteal muscle
- Absence of septum pellucidum
- Absence of Tibia
