The following categorisation of the disorder demonstrates its heterogeneity:
Common hereditary elliptocytosis (in approximate order from least severe to most severe)
With asymptomatic carrier status - individuals have no symptoms of disease and diagnosis is only able to be made on blood film
With mild disease - individuals have no symptoms, with a mild and compensated haemolytic anaemia
With sporadic haemolysis - individuals are at risk of haemolysis in the presence of particular comorbidities, including infections, and vitamin B12 deficiency
With neonatal poikilocytosis - individuals have a symptomatic haemolytic anaemia with poikilocytosis that resolves in the first year of life
With chronic haemolysis -  individual has a moderate to severe symptomatic haemolytic anaemia (this subtype has variable penetrance in some pedigrees)
With homozygosity or compound heterozygosity - depending on the exact mutations involved, individuals may lie anywhere in the spectrum between having a mild haemolytic anaemia and having a life-threatening haemolytic anaemia with symptoms mimicking those of HPP (see below)
With pyropoikilocytosis (HPP) - individuals are typically of African descent and have a life-threateningly severe haemolytic anaemia with micropoikilocytosis (small and misshapen erythrocytes) that is compounded by a marked instability of erythrocytes in even mildly elevated temperatures (pyropoikilocytosis is often found in burns victims and is the term is commonly used in reference to such people)
South-east Asian ovalocytosis (SAO) (also called stomatocytic elliptocytosis) - individuals are of South-East Asian descent (typically Malaysian, Indonesian, Melanesian, New Guinean or Filipino, have a mild haemolytic anaemia, and has increased resistance to malaria
Spherocytic elliptocytosis (also called hereditary haemolytic ovalocytosis) - individuals are of European descent and elliptocytes and spherocytes are simultaneously present in their blood

History
Elliptocytosis was first described in 1904, and was first recognised as a hereditary condition in 1932.
A clinically significant haemolytic anaemia occurs only in 5-10% of sufferers, with a strong bias towards those with more severe subtypes of the disorder.Southeast Asian ovalocytosis and spherocytic elliptocytosis are less common subtypes predominantly affecting those of south-east Asian and European ethnic groups, respectively.