[Rapid detection of alpha-thalassemia of Southeast Asian deletion by polymerase chain reaction and its application to prenatal diagnosis].

OBJECTIVE

To establish a rapid and simple polymerase chain reaction (PCR) method for detecting alpha-thalassemia of Southeast Asia deletion, and apply it to the prenatal diagnosis for high risk fetuses.

METHODS

Two pairs of primers were designed: one pair bridging the breakpoints to identify the specific deletion, the other located in the common deletion region of --(SEA), -alpha(3.7) and -alpha(4.2) gene to detect the normal chromosomes. In this system, the two amplifications ran in the same PCR tube under identical condition.

RESULTS

A 740 bp fragment was amplified in chromosomes with --(SEA) determinant and a 1,052 bp fragment in normal chromosomes. For prenatal diagnosis, 3 of 8 at-risk cases were diagnosed as normal, 3 as heterozygotes, and 2 as homozygotes of --(SEA) deletion.

CONCLUSION

This detection method is rapid and accurate and can be used as a routine method for carrier detection and prenatal diagnosis.