Detection of α‐thalassemia‐1 (Southeast Asian type) and its application for prenatal diagnosis

Abstract

A simple non‐radioactive method based on the polymerase chain reaction was used to detect the Southeast Asian type of α‐thalassemia 1 (–). Three oligonucleotide primers, one of which was adjacent to the breakpoint of the α‐thalassemia‐1 allele, were used to amplify the 570 and 194 bp DNA fragments. The 570 bp product was specific to the α‐thalassemia‐1 determinant and the 194 bp fragment was amplified from either the α‐thalassemia‐2 (‐α) or normal α‐globin (αα) determinants. In Hb Bart's hydrops fetalis (–/–), only the 570 bp fragment was obtained, whereas the 194 bp fragment was amplified in normal individual (αα/αα) and α‐thalassemia‐2 trait (‐α/αα). Both 570 and 194 bp fragments were detected in α‐thalassemia‐1 trait (–/αα) and Hb H patients (–/‐α). This procedure is useful for the rapid screening of α‐thalassemia‐1 trait and prenatal diagnosis of Hb Bart's hydrops fetalis in populations with a high frequency of the Southeast Asian Type of α‐thalassemia‐1. Copyright © 1995, Wiley Blackwell. All rights reserved