Clinical experience regarding the accuracy of NIPT in the detection of sex chromosome abnormality.

ABSTRACT

BACKGROUND: The present study aimed to determine the accuracy (Z-value) of non-invasive prenatal testing (NIPT) results for sex chromosome aneuploidy (SCA) in routine clinical practice. METHODS: Among a cohort of 12505 pregnant females, maternal plasma samples collected from our hospital were utilized for SCA analysis by NIPT detection. The positive samples were validated through an invasive procedure and karyotyping analysis. The predictive value from positive samples in sex chromosomes was compared to analyze the accuracy of the Z-value. RESULTS: There were 65 females with sex chromosome abnormalities within 12,505 pregnant females in the NIPT detection, which was validated by karyotype analysis of amniotic fluid puncture through sequencing, as well as bioinformatics analysis, with 18 true-positive samples. The true-positive results with 45,X, 47,XXY, 47,XXX and 47,XYY karyotypes predicted by NIPT were 14.29%, 50.00%, 66.67% and 71.43%, respectively. Among sex chromosome cases, the findings indicated that positive NIPT results with Z ≥ 9 show a higher accuracy. CONCLUSIONS: The findings of the present study demonstrate that the positive predictive value of NIPT for sex chromosome abnormalities is distinctive. The positive predictive value was highest for 47,XYY and lowest for 45,X. Additionally, the Z-value results are considered to be correlated with the accuracy of NIPT, although further studies need to be made.