- Paine syndrome
- Pallister-Hall syndrome
- Pancreatic beta cell agenesis
- Pancreatic cancer
- Panic disorder
- Parkinson disease
- Paroxysmal nocturnal hemoglobinuria
- Patau syndrome
- Patent ductus arteriosus
- Pedigree analysis
- Pelizaeus-Merzbacher disease
- Pendred syndrome
- Pervasive developmental disorders
- Peutz-Jeghers syndrome
- Pfeiffer syndrome
- Pharmacogenetics
- Phenylketonuria
- Pierre-Robin sequence
- Pituitary dwarfism
- Poland anomaly
- Polycystic kidney disease
- Polycystic ovary syndrome
- Porphyrias
- Prader-Willi syndrome
- Prion diseases
- Progeria syndrome
- Propionic acidemia
- Prostate cancer
- Proteus syndrome
- Prune-belly syndrome
