We have calculated the relative frequency and the birth prevalence of
lysosomal storage diseases (LSDs) in The Netherlands based on all 963 enzymatically confirmed cases diagnosed during the period 1970-1996. The combined birth prevalence for all LSDs is 14 per 100,000 live births.
Glycogenosis type II is the most frequent
LSD with a birth prevalence of 2.0 per 100,000 live births, representing 17% of all diagnosed cases. Within the group of
lipidoses,
metachromatic leukodystrophy (MLD) is the most frequent
LSD. MLD was diagnosed in 24% of
lipidoses and the calculated birth prevalence was 1.42 per 100,000 for all types combined.
Krabbe disease, diagnosed in 17% of cases, also belongs to the more frequent
lipid storage diseases in The Netherlands with a birth prevalence of 1.35 per 100,000. The birth prevalence of
Gaucher disease, commonly regarded as the most frequent
lipid storage disease is 1.16 per 100,000 for all types combined. The combined birth prevalence for all
lipid storage diseases is 6.2 per 100,000 live births. Within the group of
mucopolysaccharidoses (MPSs), MPS I has the highest calculated birth prevalence of 1.19 per 100,000 (25% of all cases of MPS diagnosed), which is slightly more frequent than
MPS IIIA with an estimated birth prevalence of 1.16 per 100,000. As a group, MPS III comprises 47% of all MPS cases diagnosed and the combined birth prevalence is 1.89 per 100,000 live births. The birth prevalence of MPS II is 0.67 per 100,000 (1.30 per 100,000 male live births). All other MPSs are rare. The combined birth prevalence for all MPSs is 4.5 per 100,000 live births.
Mucolipidoses and oligosaccharidoses are very rare with birth prevalences between 0.04 and 0.20 for individual diseases. Only 49 cases were diagnosed between 1970 and 1996. Their combined birth prevalence is 1.0 per 100,000 live births.