The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong

INTRODUCTION

Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM.

METHODS

The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling.

RESULTS

In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years.

CONCLUSION

The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Crystallization and preliminary X-ray diffraction studies of glycerol 3-phosphate cytidylyltransferase from Staphylococcus aureus

Glycerol 3-phosphate cytidylyltransferase from Staphylococcus aureus (TarD(Sa)) has been expressed in Escherichia coli, purified to homogeneity and crystallized. The strategy used for determining crystallization conditions employed hanging-drop sparse-matrix screens and required a combination of three different optimization approaches. Specifically, the presence or absence of cofactors needed to be surveyed, the effects of small-molecule additives required exploration and the rate of vapour-diffusion had to be varied in order to obtain crystals of TarD(Sa) suitable for diffraction studies. Crystals thus obtained belong to the space group P3(1)21, with unit-cell parameters a = b = 92.2, c = 156.1 A, and contain four TarD(Sa) molecules per asymmetric unit. The resolution limit observed for these crystals using synchrotron radiation is 3.0 A.