The Intensively Follow-up Examinations for Asymptomatic MPS I Infants From Nationwide Newborn Screening Program for Mucopolysaccharidoses in Taiwan.

MPS I newborn screening has been executed in Taiwan nationwide since August 2015. Infants who failed the recheck at recall were referred to MacKay Memorial Hospital for a detailed confirmatory diagnosis. Urinary first-line biochemistry examinations including urinary GAG quantification (DMB/Cre. ratio), two-dimensional electrophoresis (2-D EP), and tandem mass spectrometry assay for predominant disaccharides derived from GAGs (i.e. CS, DS, HS, and KS) were performed. If the results were positive, a confirmative diagnosis was made according to the results of leukocyte enzymatic assay and molecular DNA analysis. Up to January 31, 2019, a total of 390,793 infants had been analyzed for MPS I, in those 11 suspicious cases were referred to MacKay Memorial Hospital for confirmation. The recall rates of MPS I was 0.0028%. Four of the 11 infants were confirmed to have MPS I. The prevalence rates of MPS I was 1.02 per 100,000 live births, respectively. Infants suspected of having MPS with a positive laboratory diagnosis but without any typical, clinical manifestations are not conformed to receive ERT under the treatment guideline of ERT for MPS in Taiwan. Distinctly, the clinical manifestations of MPS are irreversible and would be worse progressively while the symptoms have shown up. Receiving ERT at this time would effectively prevent the progression of illness, but, cannot rescue or reform the irreversible physical problems. By proceeding and undergoing an intensively long-term regular physical and laboratory examinations for asymptomatic infants with MPS I can effectively control the possibility of giving an ERT in a timely fashion.