Utility and Importance of Accurate Hb A₂ Measurements for Defining a Strategy for β-Thalassemia Screening: Experience in the Balearic Islands, Spain

Abstract

The high heterogeneity in regional profiles of β-thalassemia (β-thal) mutations highlights the need for population-specific carrier detection strategies. Our aim was to analyze the relationship between hematological values and β⁰ and β⁺ mutations in 154 Balearic β-thal heterozygotes, in order to establish the most optimized mutation carrier detection strategy to be used to manage the disease in our population. The Hb A₂ level was the best parameter for discriminating between both types of carriers. Taking into account the cut-off point value of 4.85% (Hb A₂), obtained by a receiver-operating characteristic (ROC) curve analysis, we proposed an algorithm that would use a real-time polymerase chain reaction (RT-PCR) hybridization probe assay technique to detect one of the two most common mutations in the Balearic population, namely codon 39 (C>T) and IVS-I-110 (G>A), depending on the Hb A₂ value of the patient.

• Hb A₂
• β-Thalassemia (β-thal)
• Carrier screening
• β⁰- And β⁺-thalassemia mutations