Dominant Sickle Cell Disease Sickle Cell Trait with a Severe Pyruvate Kinase Deficiency Request inclusion into relevant ontology None SCDO (Jade Hotchkiss) A sickle cell disease phenotype in which an individual heterozygous for hemoglobin S also has a severe pyruvate kinase deficiency, which lowers the hemoglobin oxygen affinity, resulting in hemoglobin S polymerization and sickling.