Consistency between quantitative fluorescent-polymerase chain reaction and karyotyping in prenatal diagnosis / 中华围产医学杂志

ABSTRACT

Objective:To analyze the consistency between karyotyping and quantitative fluorescent- polymerase chain reaction (QF-PCR) in prenatal diagnosis.Methods:This study retrospectively analyzed the clinical data of 10 967 patients undergoing karyotyping and QF-PCR for prenatal diagnosis in Guangzhou Women and Children's Hospital from January 2010 to December 2017. The failure rate, results, and diagnosis of common chromosomal disorders of the two methods were compared. The sensitivity and specificity of QF-PCR in detecting chromosomal mosaicism were evaluated using the receiver operative characteristic (ROC) curve.Results:(1) The failure rates of karyotyping and QF-PCR were 0.99% (109/10 967) and 0.10% (11/10 967), respectively. (2) The karyotypes of 9 960 out of the 10 858 successfully cultured samples were normal, and 99.89% (9 949/9 960) results were consistent between the two methods. The other 898 cases included 694 (77.28%) with common chromosomal abnormalities (trisomy 21, 18 and 13 and sex chromosomal abnormality) and 204 (22.72%) with other chromosomal abnormalities. The consistency between the two methods in detecting common chromosomal abnormalities was 95.68% (664/694). (3) The consistency in the detection of trisomy 21, 18 and 13 and sex chromosomal abnormality between karyotyping and QF-PCR were 99.74% (382/383), 100.00% (125/125), 100.00% (33/33) and 81.05% (124/153). However, the common chromosomal mosaicism was only noted for 44.44% (24/54). (4) Among cases with a mosaic ratio over 18.5%, the sensitivity and specificity of QF-PCR were 0.958 (95% CI 0.789-0.999) and 0.600 (95% CI 0.406-0.773) with the area under the ROC curve (AUC) of 0.811 (95% CI 0.696-0.926, P<0.001). (5) Thirty cases with negative QF-PCR results but positive mosaic chromosomal aberrations were followed up. Ten (33.3%) pregnant women terminated their pregnancies, and two (6.7%) were lost to follow-up. The other 18 cases delivered healthy neonates that all survived after birth. Conclusions:In prenatal diagnosis, QF-PCR and karyotyping were highly consistent in the detection of trisomy 21, 13, and 18, but have significant discordance in the diagnosis of sex chromosomal abnormality.