DNA Extraction from Dried Blood Spots

For all cases, two DBS punches each 3 mm in diameter were obtained from the Neonatal Screening Biobank in the Danish National Biobank. DNA was extracted as previously described [29 (link)], with the two DBS punches being incubated in 1000 μl lysis buffer (600 μl PBS BSA (0.04%), 360 μl Bacterial Lysis Buffer (Roche, Mannheim, Germany) and 40 μl proteinase K (Roche) for 1 h at 55 °C with continuous shaking at low speed. DNA was afterwards extracted from the lysate using a NucliSens easyMAG (bioMérieux) according to manufacturer guidelines using their Specific A protocol with an additional internal lysis step.
For the control group, group, DNA was extracted from 200 μl urine using a NucliSens easyMAG (bioMérieux) according to manufacturer guidelines. The Specific A protocol was used with a final elution volume of 70 μl.