Abstract

The Quebec Neonatal Urine Screening Program was initiated in 1971 with overall screening inception of newborns in 1973. Forty-seven years later, over 3.5 million babies have been screened for up to 25 inborn errors of metabolism divided into two groups: (1) urea cycle disorders and organic acidurias; and (2) disorders of amino acid metabolism and transport. The main goal of this preventive genetic medicine program is the detection of treatable diseases before the onset of clinical symptoms. Urine specimens from 21-day-old babies are collected and dried on filter paper by parents at home. The participation is voluntary with a high compliance rate over the years (~90%). Specimens are analyzed by thin layer chromatography (TLC). The main objective of this evaluative research project was to assess the feasibility of a technological upgrade towards mass spectrometry. A 2.85-min flow injection method was devised, normal values established, and abnormal profiles confirmed using second-tier tests. The validated assays are sensitive, specific, and suitable for populational screening, as well as for high-risk screening laboratories. Triple H syndrome, which would not be detected in newborns by blood screening at two days of age was found to be positive in the urine of an affected patient.

Highlights

  • Newborn screening (NBS) for inborn errors of metabolism (IEM) was first introduced in the Province of Quebec in 1973 as part of major endeavors by the Quebec Network of Genetic Medicine (QNGM) supported by the Quebec Ministry of Health and Social Services [1]

  • NBS programs were initiated in Quebec City, quality controls (QCs), employing dried blood spots (DBS) collected at two days of age by heel prick at participating hospitals; dried urine spots (DUS) were analyzed in Sherbrooke, QC, initially collected at five days of age before discharge from the nursery [2]

  • More than 3,500,000 babies have been screened by the urinary NBS program for up to 25 inherited Mendelian disorders separated into two groups: (1) severe disorders requiring immediate therapeutic intervention and (2) disorders of amino acid metabolism and transport, requiring surveillance and follow-up

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Summary

Introduction

Newborn screening (NBS) for inborn errors of metabolism (IEM) was first introduced in the Province of Quebec in 1973 as part of major endeavors by the Quebec Network of Genetic Medicine (QNGM) supported by the Quebec Ministry of Health and Social Services [1]. The infrastructure of the NBS urine program is a unique opportunity to pursue important research projects, always with the informed consent of parents [4] The use of MS/MS offers many advantages, compared to TLC, for urine NBS in Quebec: (1) possibility of absolute quantitation when calibration curves and internal standards (IS) are used; (2) direct normalization of urine concentration according to the creatinine concentration; (3) availability of external QCs and proficiency testing for the majority of the targeted biomarkers; (4) greater flexibility for the addition of disorders to be screened; and (5) better selectivity, less interferences.

Ethics Approval
Urine Specimens Collected on Filter Paper
Reagents
Standard Working Solutions Kairos Amino Acid Second-Tier Test
Internal Standard Solutions Screening Test
Quality Controls
Organic Acids Second-Tier Test
Kairos Amino Acid Second-Tier Test
Screening Test
Findings
Analysis of Positive Cases
Full Text
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