Prenatal detection of beta-thalassemia CD17 (A-->T) mutation by polymerase chain reaction/ligase detection reaction/capillary electrophoresis for fetal DNA in maternal plasma--a case report.

OBJECTIVES

It was the aim of this study to investigate the feasibility of polymerase chain reaction (PCR)/ligase detection reaction (LDR)/capillary electrophoresis for the detection of paternally inherited fetal CD17 (A-->T) mutation of beta-thalassemia in maternal plasma.

METHODS

The target DNA in maternal plasma was amplified by PCR and the mutant signal was detected by LDR. Unique LDR products were produced and separated by capillary electrophoresis. PCR/LDR/capillary electrophoresis was applied to detect CD17 (A-->T) mutation in an experimental model at different sensitivity levels and from 3 maternal plasma samples.

RESULTS

The sensitivity of PCR/LDR/capillary electrophoresis for detecting low-abundance CD17 (A-->T) mutation was 1:5,000 at least. The technique was applied in maternal plasma DNA for detecting paternally inherited fetal CD17 (A-->T) mutation, and the results were concordant with that of PCR/reverse dot blot of amniotic fluid cell DNA.

CONCLUSIONS

PCR/LDR/capillary electrophoresis has a very high sensitivity to distinguish low-abundance single nucleotide differences and probably detects paternally inherited fetal point mutations in maternal plasma.