We conducted molecular analysis for 60 MPS-affected patients [MPS I (n = 30) (Hurler syndrome = 17, Hurler-Scheie syndrome = 13), and MPS II (n = 30) (severe = 18, attenuated = 12)] and identified a total of 44 [MPS I (n = 22) and MPS II (n = 22)] different pathogenic variants comprising missense, nonsense, frameshift, gross deletions and splice site variants.
An incidence of approximately 1 in 107,000 live births was obtained for MPS IH (Hurler phenotype); 1 in 320,000 live births (1 in 165,000 male live births) for MPS II (Hunter Syndrome); 1 in 58,000 for MPS III (Sanfilippo Syndrome); 1 in 640,000 for MPS IVA (Morquio Syndrome type A), and 1 in 320,000 for MPS VI (Maroteaux-Lamy Syndrome).
Storage disorders such as Gaucher disease, Hurler syndrome and Hunter syndrome, genetic deficiencies that affect a broad range of tissue types, may also be amenable to treatment by gene transfer into hematopoietic cells, owing to the release of enzyme expressed in transduced cells with subsequent uptake by untransduced cells ("metabolic cross-correction").