ABSTRACT
OBJECTIVE: To assess the value of noninvasive fetal trisomy testing based on massively parallel sequencing for the detection of chromosomal deletions and duplications. METHODS: Peripheral venous blood was taken from pregnant women with a high risk. Free fetal DNA in maternal plasma was used for library construction and subjected to massively parallel sequencing. Positive results were validated by traditional karyotype analysis or array-CGH. Phenotype of the fetus was observed through patholoical evaluation. RESULTS: Thirteen out of 629 cases were suspected to harbor chromosomal aberrations, which included 9 aneuploid cases and 4 structural abnormalities. The latter included one case with dup (18q) (14.35 Mb), del (18q) (21.34 Mb), one with dup (3q) (35 Mb) and two with dup (7q) (7.0 Mb). Among these, dup (18q ) (14.35 Mb), del (18q) (21.34 Mb) and dup (3q) (35 Mb) were confirmed by karyotype analysis and patholoical evaluation. However, the two cases with dup (7q) were validated by karyotype analysis and array-CGH as false positives. The phenotype with the fetus also presented as normal. CONCLUSION: The introduction of maternal plasma sequencing for prenatal testing could dramatically improve the efficiency for detecting large, partial (> 10 Mb) chromosomal deletions and duplications.
