Molecular Prenatal Diagnosis of α-Thalassemia Using Real-Time and Multiplex Polymerase Chain Reaction Methods

Abstract

Molecular analysis of two fetuses at high risk of α-thalassemia (α-thal), and their family members, was performed using real-time polymerase chain reaction (PCR) with SYBR Green 1 (SYBR-PCR) dye combined with dissociation curve analysis and multiplex PCR (m-PCR) and DNA sequencing techniques. The genotype of the fetus from one family was – –^SEA/– –^SEA (Southeast Asian deletion), which produces hydrops fetalis syndrome. The genotype of the parents was – –^SEA/αα. A boy with Hb H disease and his sibling fetus from the other family had the genotype – –^SEA/α^CSα [the Hb Constant Spring (CS) mutation: α142, Term→Gln (TAA>CAA in α2)] and αα/αα (normal), respectively. The diagnosis, based on SYBR-PCR combined with dissociation curve analysis, was in agreement with the results from the m-PCR method. This indicates that these are alternative and reliable assays for the molecular diagnosis of deletional α-thal.

Keywords:

• α-Thalassemia (α-thal)
• Real-time polymerase chain reaction (PCR)
• Dissociation curve analysis
• Multiplex PCR (m-PCR)
• Prenatal diagnosis