- Persistence of hemoglobin F (HP:0011904): Hemoglobin F (HbF) contains two globin alpha chains and two globin gamma chains. It is the main form of hemoglobin in the fetus during the last seven months of intrauterine development and in the half year of postnatal life. In adults it normally makes up less than one percent of all hemoglobin. This term refers to an increase in HbF above this limit. In beta thalassemia major, it may represent over 90 percent of all hemoglobin, and in beta thalassemia minor it may make up between 0.5 to 4 percent. Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:251380)
- HbS hemoglobin (HP:0045047): Presence of an abnormal type of hemoglobin characterized by the substitution of a glutamic acid residue at position 7 following the initial methionine residue by a valine (the mutation causative of sickle cell disease). The mutation promotes the polymerization of the HbS under conditions of low oxygen concentration. HbS can be identified by multiple methodologies including hemoglobin electrophoresis and high-performance liquid chromatography. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:251380)
- Retinopathy (HP:0000488): Any noninflammatory disease of the retina. This nonspecific term is retained here because of its wide use in the literature, but if possible new annotations should indicate the precise type of retinal abnormality. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Asplenia (HP:0001746): Absence (aplasia) of the spleen. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Reticulocytosis (HP:0001923): An elevation in the number of reticulocytes (immature erythrocytes) in the peripheral blood circulation. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Abdominal pain (HP:0002027): An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) and perceived to originate in the abdomen. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Pulmonary infiltrates (HP:0002113). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Arthralgia (HP:0002829): Joint pain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Hypochromic microcytic anemia (HP:0004840): A type of anemia characterized by an abnormally low concentration of hemoglobin in the erythrocytes and lower than normal size of the erythrocytes. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Increased red cell sickling tendency (HP:0008346). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Severe infection (HP:0032169): A type of infection that is regarded as a sign of a pathological susceptibility to infection because of unusual severity or intensity of the infection. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
- Splenic infarction (HP:0034336): Ischemia and necrosis of part or all of the spleen resulting from compromise of blood supply resulting from arterial or venous occlusion. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:251380)
These phenotypes are associated with the disease Hereditary persistence of fetal hemoglobin-sickle cell disease syndrome (ORPHA:251380).