Abstract:

Objective To investigate the value of gene analysis of amniotic fluid exfoliated cells and the neutrophil respiratory burst assay of embryo cord blood in prenatal diagnosis of high-risk fetuses with chronic granulomatous disease (CGD). Methods Six patients with CGD who were diagnosed by the Children's Hospital of Chongqing Medical University through the gene analysis were selected, including five cases of X-linked CGD (X-CGD) and one case of autosomal recessive CGD (AR-CGD). Eight samples of amniotic fluid were obtained by the amniocentesis for eight high-risk fetuses in six pedigrees. The RNA and DNA of amniotic fluid exfoliated cells were extracted. CYBB and CYBA genes were amplified by the polymerase chain reaction (PCR) and the sequencing was performed on the PCR products. Embryo blood samples were collected from two high-risk fetuses by percutaneous umbilical blood sampling. Neutrophil respiratory burst assays were conducted by the flow cytometry and the analysis of above genes was performed. Results The analytical results of CYBB and CYBA genes of amniotic fluid exfoliated cells showed that among seven cases of five X-CGD pedigrees, one female fetus and one male fetus were normal; mutated genes carried by two female fetuses were unidentified; two male fetuses were X-CGD patients; one male fetus was suspicious X-CGD patient; and one female fetus of one AR-CGD pedigree was suspicious AR-CGD patient. The respiratory burst function of neutrophil in embryo cord blood samples of the two suspicious CGD fetuses was very low. The genes analysis of above two embryo cord blood samples identified one X-CGD male fetus and one AR-CGD female fetus. Four healthy fetuses were delivered smoothly and four CGD fetuses were artificially aborted. Conclusion The gene analysis of amniotic fluid exfoliated cells combined with the respiratory burst assay of neutrophil in embryo cord blood can provide reliable prenatal diagnosis for high-risk fetuses with CGD.

Key words: amniotic fluid exfoliated cells, embryo cord blood, gene analysis, respiratory burst assay, chronic granulomatous disease