Table 1.
Risk of false positive and false negative NIPT scores for chromosomes 21, 18, and 13 in a cohort of pregnant women with a known maternal malignancy (n = 26)
| NIPT Profile in Plasma cfDNA | Copy Number Profile in Tumor DNAa | |||||
|---|---|---|---|---|---|---|
| chr21 | chr18 | chr13 | chr21 | chr18 | chr13 | |
| Number of cases with normal z > −3 and z < 3 | 22 | 22 | 20 | na | na | na |
| Number of cases with z ≥ 3 | 2 | 2 | 2 | 2/2 | 2/2 | 2/2 |
| Number of cases with z ≤ −3 | 2 | 2 | 4 | 2/2 | 2/2 | 3/4 |
| Percentage of false positive NIPT scores (%) | 15.4 | 15.4 | 19.2 | |||
| Theoretical risk of false negative NIPT scores (%) | 7.7 | 7.7 | 15.4 | |||
Abbreviations: cfDNA, cell‐free DNA; chr, chromosome; na, not applicable; z, z‐score.
a
Low‐pass sequencing (0,1 × coverage) of matched tumor biopsy DNA.