- Severe combined immunodeficiency
- Severe congenital neutropenia
- Severe dystrophinopathy, Duchenne type
- Sewaga syndroom
- Sfingolipidose
- SGA
- Shaky legs syndrome
- Shwachman Diamond syndroom
- Shwachman syndroom
- Shwachman-Bodian-Diamond syndroom
- Shwachman-Diamond syndroom
- Sicca syndroom
- Sideroblastische anemie
- Sikkelcelanemie
- Sikkelcelziekte
- Silver-Russell syndroom
- Sjögren syndroom
- Sjögren-Gougerot syndroom
- Sjögren-Larssonsyndroom
- SJS-TEN
- skeletspierkanaalziekten
- skeletspierkanalopathieën
- Skeletspierziekte
- Slaapparalyse
- Slaapziekte
- SLE
- Slechthorendheid
- Slechtziend
- Slokdarmafsluiting
- Slokdarmatresie
- Slokdarmkanker
- SM-AHNMD
- SMA
- SMA type 1
- SMA type 2
- SMA type 3
- SMA type 4
- SMA1
- SMA2
- SMA3
- SMA4
- Small for gestational age
- SMARD1
- SMARD2
- SMD
- Smith-Lemli-Optiz syndroom
- Smith-Magenis syndroom
- Somatotroop adenoom, Acromegalie
- Somatotropinoom
- Sotos syndroom