Molecular Diagnosis of α⁰-Thalassemia Through Urine DNA: A Novel DNA Source to Facilitate Prevention Programs in Remote Geographical Areas

Abstract

We assessed whether urinary DNA sediment was a feasible sample type for the molecular diagnosis of α-thalassemia (α-thal) mutations. Urine samples (5–10 mL) were collected from 218 male and female volunteers. The cells were centrifuged, and DNA was isolated according to the protocol of a commercial DNA isolation kit. Detection of the α⁰-thal [Southeast Asian (– –^SEA) and – –^THAI] deletions was performed using quantitative real-time polymerase chain reaction (q-PCR), in addition to conventional gap-PCR. The results revealed that DNA extracted from urinary sediment presented an average DNA content of 11.2 ± 5.5 ng/µL, and the 260/280 ratio indicative of DNA purity, was 1.2 ± 0.2. The overall q-PCR threshold cycle was 31.2 ± 2.3. The melting temperature for the – –^SEA deletion was 87.3 ± 0.1 °C, while that of the wild type sequence was 92.5 ± 0.2 °C. There were 16 (7.3%) α⁰-thal SEA genotypes detected. These results were in agreement with those of the conventional gap-PCR and blood DNA analyses. Thus, DNA from urinary sediment can be efficiently used for the molecular diagnosis of α⁰-thal mutations. This approach allows for rapid diagnosis, is non invasive, and could be useful for preventing Hb Bart’s (γ4) hydrops fetalis syndrome.

• α⁰-Thalassemia (α⁰-thal)
• molecular diagnosis
• mutation
• urine DNA

Declaration of interest

This study was supported by the University of Phayao, Phayao, Thailand Endowment Fund. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.