Masked β-Thalassemia Carrier Status Due to Coinherited HBD Variant Identified Through Whole Exome Sequencing: A Paediatric Case Report

Summary

A paediatric case report showing how a coinherited HBD variant (Hb A2-Yialousa) can mask β-thalassemia carrier status on routine HbA2-based HPLC screening by keeping HbA2 levels normal/low - identified incidentally alongside a pathogenic HBB splice variant during posthumous WES for suspected familial cardiomyopathy, underscoring the need for molecular testing when lab findings and family history are discordant.