Benn P, Zhang J, Lyons D, Xu W, Leonard S, Demko Z. Accuracy of fetal fraction measurements in a single-nucleotide polymorphism-based noninvasive prenatal test.
Prenat Diagn 2024. [PMID:
38991760 DOI:
10.1002/pd.6634]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/30/2024] [Accepted: 07/03/2024] [Indexed: 07/13/2024]
Abstract
BACKGROUND
Noninvasive prenatal testing (NIPT) for fetal aneuploidy relies on the analysis of fetoplacental cell-free DNA (cfDNA) found in maternal plasma. A minimum cfDNA fetal fraction (FF) is required for reliable test performance, but some methods may have suboptimal accuracy for FF measurement. This study investigated the accuracy of a single-nucleotide polymorphism- (SNP-) based NIPT method to assess FF.
METHODS
FF measurements using SNP-based NIPT in consecutive samples from singleton male pregnancies were compared with FF measured using a "gold standard" Y-chromosome method.
RESULTS
In a cohort of 106,846 samples, the SNP-based FF method showed a standard deviation (SD) of 0.42%. Compared to the Y chromosome FF method, a correlation coefficient, r, of 0.995, and bias of 0.17% were observed. The SD was not substantially different across specific FF ranges or for samples with high-risk NIPT results.
CONCLUSIONS
The SNP-based NIPT method estimates FF with good accuracy, with a SD three to eight times better than other NIPT methods (0.42% vs. 1.3%-3.4%). FF is an important quality control parameter and should be routinely reported as part of NIPT.
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