Previous studies on the incidence of the various types of mucopolysaccharidoses (MPS) in different populations have shown considerable variation. However, information regarding the incidence of MPS in the Asian population is lacking. An epidemiological study of the MPS disorders in Taiwan using multiple ascertainment sources was undertaken, and incidences of different types of MPS during the period of 1984-2004 were estimated. We compared our data with previous reports in different populations. The combined birth incidence for all MPS cases was 2.04 per 100,000 live births. MPS II (Hunter syndrome) had the highest calculated birth incidence of 1.07 per 100,000 live births (2.05 per 100,000 male live births), comprising 52% of all MPS cases diagnosed. The birth incidences of MPS I (Hurler syndrome), III (Sanfilippo syndrome), IV (Morquio syndrome), and VI (Maroteaux-Lamy syndrome) were 0.11, 0.39, 0.33, and 0.14 per 100,000 live births, respectively, which accounted for 6%, 19%, 16%, and 7% of all MPS, respectively. No cases of MPS III D (Sanfilippo syndrome type D), MPS IV B (Morquio syndrome type B), MPS VII (Sly syndrome) or MPS IX were ascertained during the study period. Overall incidence of MPS in Taiwan was consistent with that reported in Western populations. However, in contrast to the higher incidence of MPS I in most Western populations, this study showed a higher incidence of MPS II in Taiwan. It remains to be investigated whether this discrepancy is attributed to the under-diagnosis of MPS I in Taiwan or to ethnic differences.

Background-Fabry disease is a treatable lysosomal storage disorder, which is often misdiagnosed or belatedly diagnosed. Methods and Results-To determine the disease incidence in the Taiwan Chinese population, a Fabry disease newborn screening study was initiated. A total of 110 027 newborns were screened by assaying the ␣-galactosidase A (␣-Gal A) activity using dry blood spots. Low plasma ␣-Gal A activity and presence of a Fabry mutation was demonstrated in 45 neonates (3 females). Eight different mutations were identified, including 3 known missense mutations (R112H, A143T, and R356W), 4 novel missense mutations (G104V, M296L, G360C, and K391T), and one known intronic mutation (IVS4ϩ919G3 A). The IVS4ϩ919G3 A mutation was most common (82% of patients). A total of 20 maternal grandparents of infants harboring this intronic mutation were evaluated by echocardiography, mutation analysis and ␣-Gal A activity assay. The intronic mutation was found in 9 grandfathers and 11 grandmothers. Of these grandparents, 3 grandfathers (33%) but none of the grandmothers had hypertrophic cardiomyopathy. Additionally, 16 males who had been diagnosed with idiopathic hypertrophic cardiomyopathy were screened by mutation analysis and ␣-Gal A activity; 4 (25%) showed deficient plasma ␣-Gal A activity in combination with the intronic mutation. Conclusion-We found an unexpected high prevalence of the cardiac variant Fabry mutation IVS4ϩ919G3 A among both newborns (Ϸ1 in 1600 males) and patients with idiopathic hypertrophic cardiomyopathy in the Taiwan

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