15th National Congress of the Portuguese Society of Clinical Chemistry, Genetics and Laboratory Medicine

Background: Hemoglobinopathies are the most common group of genetic disorders worldwide.They mainly result from autosomal recessive transmission of mutated genes behind the synthesis of globin chains, and fall into two main groups: thalassemia syndromes, and structural haemoglobin (Hb) variants.Although some Hb variants are silent in heterozygotes, they can be severe in homozygous forms.Aim: To analyse the incidence of hemoglobinopathies in all samples studied both for guided screening and incidental finding, in the last 5 years and to show up the laboratory contribution in screening these conditions.Methods: Data collection from LIS and Hospital Health Care System in our laboratory during Jan 2018 to Feb 2023.A total of 41003 samples were included in the study, 495 with directed request and 40508 for diabetes monitoring only.Hb A 2 , Hb F and Hb variants analysis was performed by HPLC.Then, electrophoresis was performed.Hb S was confirmed by the solubility test.In order to identify rare Hb variants, some samples were sent to a reference laboratory for alternative methods and/or by molecular biology analysis.Results: After eliminating the duplicates, a total of 6144 individual samples were studied, of which 199 (3.2%) had genetic Hb disorders.From 495 requested tests by physician, 71 (14.3%) had disorders, while 128 (64.3%) were suggested by lab stuff.The main condition found in the studied population were sickle cell trait (46.2%), followed by β-thalassemia minor (26.1%),Hb Lepore (11.6%), and others.Rare cases were found with co-inheritance of heterozygous alpha thalassemia and sickle trait (0.5%), and Hb E in heterozygous condition (HBB: c.79G>A; p.Glu27Lys) and compound heterozigoty in the gene HBA del-SEA / HBA2: c.369C>G; pHis123Gln (Hb Westmead) (0.5%). Conclusion:This study revealed that few genetic Hb disorders derived from oriented study.Our results also highlighted that clinical pathology service is essential in routine chromatograms analysis to screening hemoglobinopathies.Most, came of unintentional lab findings of carriers unaware of their status.Our results show a significantly higher prevalence of hemoglobinopathies compared to last Portuguese population data.In addition, those data fully justify an accurate analysis of all chromatograms.