Five years of screening for galactosaemia in South Africa: Pitfalls of using Benedict's test and thin layer chromatography to screen for galactosaemia in a developing country.
Adolescent
Child
Child, Preschool
Chromatography, Thin Layer
Copper Sulfate
DNA
/ genetics
DNA Mutational Analysis
Developing Countries
False Negative Reactions
False Positive Reactions
Female
Galactosemias
/ diagnosis
Humans
Indicators and Reagents
Infant
Male
Mass Screening
/ methods
Reproducibility of Results
Retrospective Studies
South Africa
UTP-Hexose-1-Phosphate Uridylyltransferase
/ analysis
Young Adult
Benedict's test
Galactokinase
Galactosaemia
Galactose epimerase
Galactose metabolism
Galactose-1-phosphate uridyl transferase
Sugar chromatography
Journal
Clinica chimica acta; international journal of clinical chemistry
ISSN: 1873-3492
Titre abrégé: Clin Chim Acta
Pays: Netherlands
ID NLM: 1302422
Informations de publication
Date de publication:
Jun 2020
Jun 2020
Historique:
received:
02
02
2020
revised:
15
02
2020
accepted:
17
02
2020
pubmed:
25
2
2020
medline:
18
4
2020
entrez:
25
2
2020
Statut:
ppublish
Résumé
The objective of the study was to investigate the effectiveness of screening for hereditary galactosaemia with Benedict's test and thin layer chromatography (TLC) in a tertiary laboratory from a developing country. We retrospectively analysed the results of tests done in suspected galactosaemia patients including Benedict's test, thin layer chromatography, GALT activity and DNA analysis. 878 paediatric patients were screened with Benedict's test; the age range was 5 days to 19 years. 48% tested positive/trace on the Benedict's test of which 52% of these had galactosuria evident on TLC. 22% of this sample had pathologically low GALT results on follow-up. 8 patients from the screened population were confirmed to have galactosaemia, in addition to 6 more patients diagnosed with galactosaemia without screening tests performed. Median ages at which the diagnoses were made in the screened and non-screened samples were 2 months and 6 months respectively. Confirmatory DNA testing was performed in 2 patients, whom were found to be heterozygous for S135L mutation. Inadequate performance of Benedict's test and TLC was demonstrated by false positive and false negative results leading us to conclude that screening test results require interpretation with caution.
Sections du résumé
BACKGROUND
BACKGROUND
The objective of the study was to investigate the effectiveness of screening for hereditary galactosaemia with Benedict's test and thin layer chromatography (TLC) in a tertiary laboratory from a developing country.
METHODS
METHODS
We retrospectively analysed the results of tests done in suspected galactosaemia patients including Benedict's test, thin layer chromatography, GALT activity and DNA analysis.
RESULTS
RESULTS
878 paediatric patients were screened with Benedict's test; the age range was 5 days to 19 years. 48% tested positive/trace on the Benedict's test of which 52% of these had galactosuria evident on TLC. 22% of this sample had pathologically low GALT results on follow-up. 8 patients from the screened population were confirmed to have galactosaemia, in addition to 6 more patients diagnosed with galactosaemia without screening tests performed. Median ages at which the diagnoses were made in the screened and non-screened samples were 2 months and 6 months respectively. Confirmatory DNA testing was performed in 2 patients, whom were found to be heterozygous for S135L mutation.
CONCLUSION
CONCLUSIONS
Inadequate performance of Benedict's test and TLC was demonstrated by false positive and false negative results leading us to conclude that screening test results require interpretation with caution.
Identifiants
pubmed: 32092319
pii: S0009-8981(20)30073-5
doi: 10.1016/j.cca.2020.02.018
pii:
doi:
Substances chimiques
Indicators and Reagents
0
DNA
9007-49-2
UTP-Hexose-1-Phosphate Uridylyltransferase
EC 2.7.7.10
GALT protein, human
EC 2.7.7.12
Copper Sulfate
LRX7AJ16DT
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
73-77Informations de copyright
Copyright © 2020 Elsevier B.V. All rights reserved.