Hereditary Anemias: An Overview

An approach to anemia

All children and youth new to Canada should be screened for anemia upon arrival.¹ Those who have experienced substantial poverty, such as refugees, are at particularly high risk of iron deficiency anemia. Iron deficiency anemia is often due to the complex interaction of malnutrition and chronic or recurrent gastrointestinal parasitic infestations.

Iron deficiency anemia and thalassemia are the most common causes of microcytic anemia in children. Less common causes are inflammation of chronic disease, lead toxicity and, rarely, sideroblastic anemia.²

Children and youth with microcytic anemia should be screened or treated for iron deficiency empirically. Further testing for hemoglobinopathies (using HPLC or Hb electrophoresis), including sickle cell disease and thalassemia (using hematological and genotype testing), is recommended when microcytic or normocytic anemia exists in the presence of normal iron studies, and:

• there is a clinical history consistent with these diseases
• the patient is at risk because of ethnicity or family history.

Iron deficiency and iron deficiency anemia are further discussed in the Malnutrition section of this website. 

Children and youth of certain ethnicities are at increased risk of hereditary anemias, including:

• sickle cell disease
• thalassemias
• glucose-6-phosphate dehydrogenase (G6PD) deficiency

The thalassemias and hemoglobinopathies (e.g., sickle cell disorders) affect the quantity and quality, respectively, of hemoglobin molecules within red blood cells. Poor diet and weight loss due to parasites or chronic illness can compound the adverse effects of hereditary anemias.

Health care providers should be aware that hemoglobinopathies are more common among newly arrived women from high-risk regions, and these conditions may lead to serious maternal and neonatal complications.³ Carrier screening for hemoglobinopathies is not standard practice in most parts of the world. The Society of Obstetricians and Gynaecologists of Canada recommends that women in at-risk ethnic populations be screened pre-conceptionally or as early as possible in pregnancy.⁴

More information is available in this resource about:

• sickle cell disease
• thalassemias  
• glucose-6-phosphate dehydrogenase (G6PD) deficiency

Selected resources

• American Academy of Pediatrics, Section on Hematology/Oncology and Committee on Genetics. Health supervision for children with sickle cell disease. Pediatrics 2002;109(3):526-35.
• The Hospital for Sick Children. About Kids Health [Handouts}
• The Hospital for Sick Children. 2006-07 (rev, 2010). Clinical practice guideline. Acute chest syndrome or pneumonia: Guidelines for management in children with sickle cell disease.  
• Richardson M. Microcytic anemia. Pediatr Rev 2007;28(1):5-14.
• Sayani F, Warner M, Wu J, et al, 2009. Guidelines for the clinical care of patients with thalassemia in Canada.

References

1. Pottie K, Chambers A, Brockest B, et al; Canadian Collaboration for Immigrant and Refugee Health. Appendix 15: Iron-deficiency anemia: Evidence review for newly arriving immigrants and refugees. In: Pottie K, Greenaway C, Feightner J, et al. Evidence-based clinical guidelines for immigrants and refugees. CMAJ 2011;183(12):E824-925.
2. Richardson M. Microcytic anemia. Pediatr Rev 2007;28(1):5-14.
3. Pottie K, Greenaway C, Feightner J, et al. Evidence-based clinical guidelines for immigrants and refugees. CMAJ 2011;183(12):E824-925.
4. Langlois S, Ford JC, Chitayat D, et al. Carrier screening for thalassemia and hemoglobinopathies in Canada. J Obstet Gynaecol Can 2008;30(10):950-71.

Other works consulted

• American Academy of Pediatrics, Section on Hematology/Oncology and Committee on Genetics. Health supervision for children with sickle cell disease. Pediatrics 2002;109(3):526-35.
• American Academy of Pediatrics Subcommittee on Hyperbilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics 2004;114(1):297-316.
• Jeng MR, Vichinsky E. Hematologic problems in immigrants from Southeast Asia. Hematol Oncol Clin N Am 2004;18(6):1405-22, x.
• Kasper J, Gupta N, Hunter A, et al. Care of the child immigrant. In: Gupta N, Nelson BD, Kasper J, eds. Massachusetts General Hospital Handbook of Pediatric Global Health. New York, NY: Springer, in press.
• Muncie HL, Campbell JS. Alpha and beta thalassemia. Am Fam Physician 2009;80(4):339-44.
• Piel FB, Patil AP, Howes RE, et al. Global distribution of the sickle cell gene and geographical confirmation of the malaria hypothesis. Nat Commun 2010;1:104.
• Public Health Agency of Canada 2012. Canada Immunization Guide: Evergreen edn.  
• Public Health Agency of Canada. Canadian recommendations for the prevention and treatment of malaria among international travellers – 2009: Supplement. Can Commun Dis Rep 2009;35-S1:1-82.
• Sayani F, Warner M, Wu J, et al, 2009. Guidelines for the clinical care of patients with thalassemia in Canada.
• Weatherall DJ, Clegg JB. The Thalassaemia Syndromes. 4th edn. Oxford, UK: Blackwell Sciences, 2001.
• WHO. Human genetics programme/Genomic resource centre/Genes and human disease/Monogenic diseases, Thalassemia/Figure 7: Global distribution of hemoglobin disorders, in terms of births of affected infants per 1000 births.