The study will include all newborns in Normandie region for 3 years (about 105,000 births) for whom signed consent by one (or two) parents will be collected. Based on our previous pilot study (2011) assessing MCAD and PKU using tandem mass spectrometry-based method in Normandie region in which informed consents have been signed for all newborns (43,000) but we are expecting a great willingness to participate to this project. Thus, we are aiming to include 100,000 newborns, and the study will be continued until we reach at least this target.

The primary objective is to evaluate the epidemiology of MPS1 and Pompe disease using dried blood samples in the first cohort of neonates tested in France (Normandie region).

Inclusion Criteria:

• Newborn in a Normandy maternity hospital
• Newborn participating in the National Neonatal Screening Program
• Holder(s) of parental authority having read and understood the information letter and signed the informed consent form

Exclusion Criteria:

There are no criteria for non-inclusion in this study. Participation in the study, such as participation in the National Neonatal Screening Program, is not mandatory.

Newborn