Rapid prenatal diagnosis of Hb Bart's hydrops fetalis in southeast Asia area by polymerase chain reaction.

ABSTRACT

We used the polymerase chain reaction (PCR) to amplify the breakpoint area of alpha-thalassemia-1 of Southeast Asia type and several parts of the alpha-globin gene cluster to make a differential diagnosis between alpha-thalassemia-1 and Hb Bart's hydrops fetalis. The procedure involved three primers to detect the homozygote of alpha-thalassemia-1, then amplifies the other alpha-globin gene cluster with three other pairs of primers to double check the results. The PCR products were checked again by allele specific probes. Twenty-two cases were diagnosed prenatally, two were normal, 17 were alpha-thalassemia-1, and three Hb Bart's hydrops fetalis. All cases were confirmed either by Southern blot hybridization or follow-up by sonography or after delivery. No false positive or false negative results were obtained by our strigent procedure. We conclude it to be a rapid, accurate and economic method.