Version October 2024
| HSt | SAO | |
| First line (done in all patients) | ||
| Complete blood count (CBC) | Variable degree of anemia and reticulocytosis Increased MCV, MCH, and/or MCHC | Variable degrees of anemia and reticulocytosis, typically resolves by early childhood Decreased MCV may be seen |
| Blood smear | Dehydrated HSt: <20% stomatocytes (absence of stomatocytes in some cases) Overhydrated HSt: >20% stomatocytes | Ovalocytes, stomatocytic ovalocytes/elliptocytes, or theta cells (ovalocytes with two slits) |
| Family history for inheritance pattern | Autosomal dominant | Autosomal dominant |
| Second line (at least one of these tests is done in patients with suggestive findings on first-line testing) | ||
| Osmotic fragility (OF) | Dehydrated HSt: Decreased OF Overhydrated HSt: Increased OF | (Not well studied) |
| EMA binding | Normal to increased | Decreased |
| Ektacytometry | Dehydrated HSt: Left shift of the osmolarity curve for pathogenic variants in PIEZO1 Overhydrated HSt: Right shift of the osmolarity curve | Flattening of the osmolarity curve with undeformable feature and DImax close to zero |
| Third line | ||
| Genetic testing (Sanger sequencing, NGS panel, or whole exome sequencing)* | Pathogenic variant in one of the following:
| Specific 27 base pair deletion (Δ400-408) |
CDA: congenital dyserythropoietic anemia; DBA: Diamond-Blackfan anemia; EMA: eosin-5-maleimide; HSt: hereditary stomatocytosis; MCH: mean corpuscular hemoglobin; MCHC: mean corpuscular hemoglobin concentration; MCV: mean corpuscular volume; NGS: next-generation sequencing; OF: osmotic fragility; RBC: red blood cell; SAO: Southeast Asian ovalocytosis.
* NGS panels for hereditary RBC disorders may evaluate genes that encode for membrane proteins, enzymes, iron regulatory proteins, and specific conditions such as DBA, CDAs, or sideroblastic anemias.Do you want to add Medilib to your home screen?
