Original Article Maria Christina Lopes Araujo Oliveira Rachel Aparecida Ferreira Fernandes Carolina Lins Rodrigues Daniela Aguiar Ribeiro Maria Fernanda Giovanardi Marcos Borato Viana Pediatrics Department, Universidade Federal de Minas Gerais – UFMG, Belo Horizonte, MG, Brazil Conflict-of-interest disclosure: The authors declare no competing financial interest Submitted: 8/3/2011 Accepted: 11/1/2011 Corresponding author: Maria Christina Lopes Araujo Oliveira Pediatrics Department, Universidade Federal de Minas Gerais – UFMG Av Alfredo Balena, 130 – Santa Efigênia 30130-100 – Belo Horizonte, MG, Brazil chrismariana@gmail.com www.rbhh.org or www.scielo.br/rbhh DOI: 10.5581/1516-8484.20120006 Rev Bras Hematol Hemoter. 2012;34(1):9-13 Clinical course of 63 children with hereditary spherocytosis: a retrospective study Background: Hereditary spherocytosis (HS) is an inherited hemolytic anemia that is caused by deficiency or dysfunction of erythrocyte cytoskeletal proteins. Aim: The aim of this study was to describe the clinical course of hereditary spherocytosis in patients treated in the Pediatric Hematology Unit, Hospital das Clínicas, Universidade Federal de Minas Gerais. Methods: Sixty-three under 16-year-old patients with hereditary spherocytosis were retrospectively evaluated between January 1988 and December 2007. Hereditary spherocytosis was diagnosed based on clinical history, physical examination and on a positive osmotic fragility curve. Patients underwent screening for cholelithiasis by ultrasonography. They were classified into three groups: mild, moderate and severe. The events of interest were need for blood transfusion, cholelithiasis, splenic sequestration, aplastic crisis, and splenectomy. Differences between subgroups were evaluated by the two-sided log-rank test. Results: The mean age at diagnosis was 5.2 years and most patients were classified as moderate (54%). Patients with the severe form of the disease were younger (p-value = 0.001) and needed more blood transfusions (p-value = 0.004). Seventeen patients (27%) developed cholelithiasis, 14 (22.2%) splenic sequestration and three (4.8%) aplastic crises. Twenty-two patients (34.9%) were splenectomized with the main indication being splenic sequestration in nine patients (41%). Conclusion: The clinical course of patients with hereditary spherocytosis in this study was relatively benign however cholelithiasis was a common complication. Keywords: Spherocytosis, hereditary; Cholelithiasis; Splenectomy; Child; Retrospective studies Introduction Hereditary spherocytosis (HS) is a common inherited hemolytic anemia that occurs in all racial groups but is particularly common in Caucasians from northern Europe and North America. The estimated prevalence ranges from 1:2000 to 1:5000.(1-3) The underlying primary molecular lesion is heterogeneous; it may involve several erythrocyte membrane proteins with ankyrin being the most commonly affected followed by spectrin, protein band 3, and, more rarely, protein 4.2.(4) The genetic defects identified in HS are encoded by five genes in chromosomes 1, 8, 14, 15 and 17. Approximately 75% of cases display an autosomal dominant pattern of inheritance; the others comprise of recessive forms and de novo mutations.(5,6) The deficiency or dysfunction of any one of these membrane components can weaken or destabilize the cytoskeleton whose role is to maintain the shape, deformability and elasticity of the red blood cell. This results in abnormal red cell morphology and a shorter lifespan.(6,7) The clinical manifestations of HS vary widely. The main clinical features are hemolytic anemia - which can range from compensated to a severe degree, sometimes requiring exchange transfusion at birth and/or repeated blood transfusions - variable jaundice, splenomegaly and gallstones.(3-8) The aim of the present study was to describe the clinical course of HS in patients followed up in the tertiary Pediatric Hematology Center of Hospital das Clínicas, Universidade Federal de Minas Gerais (UFMG). Methods Sixty-three patients with hereditary spherocytosis (HS) were retrospectively evaluated. All were under the age of 16 years at diagnosis and were followed at Hospital of Clinics of UFMG from January 1988 to December 2007. HS was diagnosed on the basis of clinical history, physical examination and results of laboratory tests including complete 9