[Newborn mass-screening programme for histidinaemia: increased efficiency through selective thin-layer chromatography...

Area of Science:

• Biochemistry
• Medical Genetics
• Neonatal Screening

Context:

• Histidinaemia cases were missed by traditional neonatal blood screening, necessitating improved detection methods.
• Urinary screening identified histidinaemia cases not detected by neonatal blood screening, prompting a review of diagnostic thresholds.
• The Guthrie test (GT) was the standard for neonatal screening, but its sensitivity for histidinaemia was limited.

Purpose:

• To enhance the detection efficiency of histidinaemia in newborn infants.
• To develop and validate a combined thin-layer chromatography (TLC) and Guthrie test (GT) method for improved histidinaemia screening.
• To lower the control limit for histidine detection to identify more affected infants.

Summary:

• A novel screening approach combining thin-layer chromatography (TLC) with the Guthrie test (GT) was developed, significantly increasing histidinaemia detection rates.
• The combined TLC+GT method identified twice as many histidinaemia cases compared to the GT alone, despite a substantially lower control limit for histidine.
• In 1975, 9 cases of histidinaemia were detected out of 87,729 infants, with an incidence of 1 in 9,748. Many cases had initial blood histidine levels below the previous 6 mg/dl threshold.

Impact:

• The improved screening method allows for earlier identification and management of histidinaemia, potentially preventing long-term health complications.
• The study demonstrates the value of integrating advanced chromatographic techniques with established screening tests for metabolic disorders.
• The findings support the implementation of lower diagnostic thresholds and combined testing strategies for neonatal screening programs.