Infantile Pyknocytosis

**Semantic type:** Disease or Syndrome

**Definition:** A rare, neonatal syndrome characterized by early jaundice that becomes rapidly associated with severe hemolytic anemia. The peripheral blood smear is remarkable for small irregular, contracted red blood cells with hyper-dense spikes (pyknocytes), that progressively increase in number and then spontaneously disappear.

**Synonyms:** - Hereditary Pyknocytosis