- Corticale visuele beperking
- Corticobasale degeneratie
- Corticotroof hypofyse-adenoom
- Costello Syndroom
- Cowden syndroom
- CP
- CPD IV
- CPRS
- Craniale arteritis
- Craniale malformatie
- Cranio-fronto-nasaal syndroom
- Cranio-fronto-nasale dysplasie
- Craniodysostose
- Craniofaryngeoom
- Craniofaryngioom
- Craniosynostose
- Craniosynostose
- Creutzfeldt-Jakob
- Crigler-Najjar syndroom
- Crohn’s ziekte
- Crohn-Lesniowsky syndroom
- Crouzonsyndroom
- Cryoglobulinemische vasculitis
- CSCR
- CSWS
- CSWS of ESES
- CSWSS-syndroom
- CTEPH
- CTEV
- Current pressure-sensitive neuropathy
- Cushing
- Cushing Syndroom
- Cutane leucocytoclastische angiitis
- Cutane lupus erythematodes
- Cutane lupus erythematosus
- Cutane mastocytose
- Cutis Marmorata Telangiectatica Congenita
- CV
- CVID
- Cystenieren
- Cystic fibrose
- Cystic fibrosis
- Cystinose
- Cystische fibrose