The Relevance of β-Thalassemia Heterozygosity in Pediatric Clinical Practice: Croatian Experience

Abstract

Thalassemia syndromes are common monogenic disorders that represent a significant global health issue. No systematic epidemiological and molecular investigations on thalassemias in Croatian population have been reported to date. This prospective study included 70 children with a presumptive diagnosis of thalassemia, and their 42 first-degree relatives. Molecular characterization was performed using direct sequencing and gap-PCR methods. We identified 46 (30 children and 16 first-degree relatives) β-thalassemia heterozygous carriers from 24 unrelated families, carrying eight different mutations and one hemoglobin variant. Five variants account for approximately 85% of all affected β-globin alleles: Hb Lepore-Boston-Washington (32,6%), HBB: c.93-21G>A (19,6%), HBB:c.315+1G>A (13,1%), HBB:c.92+1G>A (10,9%), and HBB:c.92+6T>C variant (8,7%). A need for more detailed genetic profiling of β-thalassemia carriers is emphasized since genetic modifiers can significantly impact their phenotype. Our study provides important new insights into the relevance of β-thalassemia heterozygosity in the pediatric clinical practice.