Table 1.

Digital RNA SNP analysis in placental tissues of euploid and T21 pregnancies

SampleGenotypeNo. of wells positive for individual alleles
mrSPRT result
A onlyG onlyAGAll negativePrUnclassifiable regionClassification
Placental DNA
    N677AG8583126900.790.510.63–0.65Euploid
    N710AG10283731260.520.550.61–0.63Euploid
    N435AGG49157130480.630.760.62–0.64T21
    N981AAG1356982980.500.660.61–0.63T21
Placental RNA
    V533AG10393711170.560.530.61–0.63Euploid
    V943AG89100741210.550.530.61–0.63Euploid
    N435AGG5213895990.480.730.61–0.63T21
    T215AAG14658138420.710.720.62–0.64T21
  • The no. of wells for all samples was 384. Genotypes were determined by mass spectrometric assay. The m r value indicates the average no. of reference molecules per reaction well. The P r values were calculated by using the following equation: no. of wells positive for the overrepresented allele/(no. of wells positive for A only + no. of wells positive for G only). The unclassifiable region for the corresponding m r is shown. “Euploid” was assigned when the P r was below the unclassifiable region; “T21” was assigned when the P r was above the unclassifiable region.