From the Guidelines
Microcytic hypochromic anemia can be caused by genetic disorders of iron metabolism or heme synthesis, such as STEAP3 defects, SLC11A2 defects, and TMPRSS6 mutations, which lead to impaired iron utilization or defective heme synthesis. These conditions can result in microcytic hypochromic anemia due to the accumulation of uroporphyrin and coproporphyrin in red blood cells, plasma, and urine, as well as increased levels of free protoporphyrin (FPP) and zinc protoporphyrin (ZnPP) in red blood cells 1. The diagnosis of these conditions can be guided by a diagnostic flowchart that takes into account clinical and laboratory assessments, including bone marrow smears and gene analysis 1.
Some of the key causes of microcytic hypochromic anemia include:
- STEAP3 defects, which can be treated with erythrocyte transfusions in combination with erythropoietin (EPO) and iron chelation 1
- SLC11A2 defects, which can be treated with oral iron supplementation, EPO, and/or erythrocyte transfusions, with monitoring of iron status to detect toxic iron loading 1
- TMPRSS6 mutations, which can cause a mild IRIDA phenotype, although the diagnosis of IRIDA due to a TMPRSS6 defect can only be made with certainty when the patient is homozygous or compound heterozygous for a pathogenic mutation 1
It is essential to consider these genetic disorders in the diagnosis and management of microcytic hypochromic anemia, as they can have significant implications for patient outcomes and quality of life.
From the Research
Causes of Microcytic Hypochromic Anemia
- Iron deficiency anemia, which can be caused by disruptions in iron balance, such as menstruation, pregnancy, and gastrointestinal bleeding 2, 3, 4, 5, 6
- Thalassemia, a genetic disorder that affects the production of hemoglobin 3, 4, 5
- Sideroblastic anemia, a disorder that affects the production of hemoglobin 3, 4
- Anemia of chronic disease, which can be caused by chronic inflammation or infection 2, 4
- Impaired hemoglobin synthesis, which can be caused by disorders of iron metabolism, protoporphyrin and heme synthesis, or impaired globin synthesis 4
- Alpha-thalassemia, a genetic disorder that affects the production of hemoglobin 5
- Iron deficiency associated with alpha-thalassemia 5
- Bleeding, such as menstrual or gastrointestinal bleeding 6
- Impaired iron absorption, such as atrophic gastritis, celiac disease, or bariatric surgical procedures 6
- Inadequate dietary iron intake 6
- Pregnancy 6
- Chronic inflammatory conditions, such as inflammatory bowel disease, chronic kidney disease, heart failure, or cancer 6