[63620725]
At the (b)(6) screening conference in the (b)(6) in september 2016, a newborn screening lab from (b)(6) reported results of a pilot study of newborn screening for lysosomal storage disorders (mps-1, pompe, fabry, pompe) using digital microfluidics fluorimetric assays provided by baebies, inc. (nc) in the talk they showed data to suggest that out of approx 10,000 newborn dried blood spots tested, they had a total of 4 screen positives (enzymatic activities below their chosen cutoff values). They showed genotype data showing that these were all false positives. People in attendance including me were surprised that they only had 4 false positives out of 10,000 given other studies with this platform and with tandem mass spectrometry. I have subsequently asked the lab in (b)(6)to provide the distribution of enzymatic activity plots, which i now have. They show clearly that the number of screen positives is about 280 out of 10,000 not 4. By comparison a recent pilot study with tandem mass spectrometry showed a 70-fold lower screen positive rate (molec. Genet. Metabol. 2016, 118, 304-9. The distribution plots are available upon request from (b)(6). Also of concern is the reported %cv for the (b)(6) fluorimetric assays in the range up to 22% (for repeat analysis of the same dried blood spot on multiple plate readers. I am concerned that at the (b)(6) mtg, the author who presented the pilot studies gave a very inaccurate picture of the rate of screen positives. Also of concern is the high rate of screen positives (and thus false positives) of this digital microfluidics platform in this pilot study.
Patient Sequence No: 1, Text Type: D, B5