Confounding factors in the diagnosis and clinical course of rare congenital hemolytic anemias

Table 3 Main diagnostic features of congenital hemolytic anemias (CHAS)

	Membrane defects	Enzyme defects	Congenital dyserythropoietic anemia
Anemia	Highly variable from severe to normal Hb values	Highly variable from severe to normal Hb values	Highly variable from very severe to nearly normal Hb values
Reticulocytes	Usually elevated except during aplastic crisis	Usually elevated except during aplastic crisis; particularly elevated in PKD after splenectomy	Usually low as referred to Hb values
Red cell morphology	Highly characteristic	Usually unremarkable	Usually unremarkable
Osmotic fragility tests, EMA binding, and ectacytometry	Typically altered	Usually uninformative	Usually uninformative
Membrane protein analysis	Informative in most cases	Useless	Usually uninformative, except for band 3 deglycosylation in CDA type II
Enzyme assays	Useless	Essential	Useless
Molecular tests	Informative particularly in HSt	Essential	Essential
Family history	Positive in most cases	Usually negative, consider consanguinity	Usually negative, consider consanguinity

Eosin 5 maleimide EMA binding; PKD pyruvate kynase deficiency; HSt hereditary stomatocytosis; CDA congenital dyserythropoietic anemia

ISSN: 1750-1172