Sideroblastic anemia in children: challenges in diagnosis and management in three cases

Abstract

Sideroblastic anemias (SAs) represent a heterogeneous group of rare hematological disorders characterized by iron accumulation in mitochondria of erythroblasts with ineffective erythropoiesis. SAs are categorized into acquired and congenital forms. Acquired, secondary, and clonal, SA is rare in pediatric populations. Congenital SA (CSA) is classified into syndromic and non-syndromic forms. Herein, we describe three cases of pediatric patients with SA. The diagnosis of SA was based on the presence of type 3 sideroblasts on BM aspirate smear (greater than 15%) and genetic tests. In the first case, the diagnosis of myelodysplastic syndrome with ring sideroblasts (MDS-RS) with somatic SF3B1 mutation was made at the age of 11 years. A whole exome sequencing did not reveal any germinal predisposition for MDS. A wait-and-see strategy was adopted. After one year- of follow-up, no blood transfusion was needed and no further cytopenia occurred. The two other children had presented anemia at an early age and were diagnosed with CSA. The first case was a girl with SCL25A38 gene mutation. For the second one, the diagnosis of aminolevulinic acid synthase 2 deficiency was considered the most plausible given the family history and the favourable response to pyridoxine. Iron overload occurred in both patients with CSA, requiring chelation therapy. In conclusion, Perls' stain remains a valuable tool for guiding the diagnosis of unexplained anemia in pediatric patients. Genetic testing is crucial for the characterization of congenital sideroblastic anemias. The incidence of myeloid neoplasms with ring sideroblasts is exceptional in children, and the long-term prognosis remains undefined.