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Table 2 Details of discordant cases

From: Positive predictive value of non-invasive prenatal screening for fetal chromosome disorders using cell-free DNA in maternal serum: independent clinical experience of a tertiary referral center

Patient NIPS result Other clinical information Fetal diagnostic genetic test results Maternal results
31 Abnormal for DSa US at 19.3w multiple anomalies consistent with T18 nuc ish (D21S259x2) on FFPE fetal tissue Not offered
32 Abnormal for DS US at 12.3w abnormal NT; US at 20.7w normal; postpartum note “delivered a male infant at 36.6w…birth weight 6 lbs 10 oz….” Declined Not offered
33 Abnormal for DS Paternal first cousin with DS; US at 13.4w normal NT; US at 16.6w normal 46,XY in all 15 amniocyte clones; arr(1-22)x2,(XY)x1 on amniocytes 46,XX in all 20 peripheral blood cells analyzed and 30 additional cells screened for 21
41 Abnormal for T18 AMA; FTS pos DS (1 in 43); US at 13.1w normal NT; US at 17.6w and 19.7w normal Declined Not offered
42 Abnormal for T18 AMA; US at 19.6w normal nuc ish(D18Z1x2)[200/200] on uncultured amniocytes; 46,XY in all 52 amniocyte clones Not offered
43 Abnormal for T18 AMA; US at 12.7w normal NT; US at 20.4w normal Declined Not offered
44 Abnormal for T18 US at 19.0w EIF; discharge exam: “Baby does not have any physical exam findings concerning for trisomy 18.” Declined Not offered
46 Abnormal for T13 AMA; US at 13.7w normal NT; US at 20.4w normal nuc ish(RB1x2)[50/50] on uncultured amniocytes; 46,XX in all 15 amniocyte clones 46,XX in all 20 peripheral blood cells analyzed and 50 additional cells screened for 13
51 Abnormal for 45,X AMA; US at 19.3 normal nuc ish(DXZ1x2), (DYZ3x0)[191/200]; 46,XX in all 21 amniocyte clones and 100 cells from mass culture 45,X[5]/46,XX[45] in peripheral blood
52 Abnormal for 45,X AMA; US at 12.3w normal NT; US at 20.3w normal nuc ish(DXZ1x2)[220/225], (DYZ3x0)[225/225] on uncultured amniocytes; 46,XX in all 16 amniocyte clones analyzed and 22 additional clones screened for 45X 46,XX in all 20 peripheral blood cells analyzed and 30 additional cells screened for X
55 Abnormal for 47,XXX US at 18.8w unilateral CPC and unilateral renal pelviectasis 46,XX in all 20 cells analyzed from peripheral blood postnatally 46,XX in all 20 peripheral blood cells analyzed and 30 additional cells screened for X
56 Abnormal for 47,XXX Quad screen pos DS 1 in 15, maternal diabetes and renal failure, US at 21.3w two-vessel cord 46,XX in all 20 cells analyzed from peripheral blood at 7 weeks of age Not done secondary to chaotic family circumstances
  1. Abbreviation:AMA advanced maternal age, CPC choroid plexus cyst, DS Down syndrome, EIF echogenic intracardiac focus, FFPE formalin-fixed, paraffin-embedded, FTS first trimester (maternal serum) screen, NT nuchal translucency, T18 trisomy 18, T13 trisomy 13, US ultrasound
  2. aResults were also abnormal for T18