Next generation sequencing for diagnosis of hereditary anemia: Experience in a Spanish reference center

Hereditary anemia (HA) encloses a wide group of rare inherited disorders with clinical and hematologic overlaps that complicate diagnosis.A 48-gene panel was developed to diagnose HA by Next Generation Sequencing (NGS) in a large cohort of 165 patients from 160 unrelated families.Patients were divided in: A) patients who had a suspicion of a specific type of HA (n = 109), and B) patients who had a suspicion of HA but with no clear type (n = 56). Diagnostic performance was 83.5% in group A and a change of the initial diagnosis occurred in 11% of these patients. In group B, 35.7% of patients achieved a genetic diagnosis. NGS identified 6 cases of xerocytosis, 6 of pyruvate kinase (PK) deficiency, 4 of G6PD, and 1 case of phytosterolemia with no initial suspicion of these pathologies, which is clinically relevant since they have specific treatment. Five patients were found to carry variants associated to two different pathologies (4 of them combining a metabolic deficiency and a membrane defect), and 44 new variants were identified in 41 patients.The use of NGS is a sensitive technique to diagnose HA and it shows better performance when patients are better characterized.