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Health Professionals Guide to Newborn Screening Galactosemia Autosomal recessive disorder of galactose metabolism. The genetic disturbance is expressed as a cellular deficiency of either, galactose-1-phosphate uridyl transferase (classic form), galactokinase, (variant) or uridine diphosphate galactose 4 epimerase (variant) - the enzymes catalyzing the reaction by which galactose is converted to glucose. The main dietary source of galactose is lactose, the principle carbohydrate in milk.
COMMENT: Although detection of classical galactosemia using the GALT enzyme test is not depended upon the feeding status, galactosemic babies that have been transfused will appear to have normal enzyme activity. This is due to the GALT activity in the red cells. To help identify galactosemic babies that have been transfused, a 2nd tier metabolite (galactose and galactose-1-phosphate) assay is performed on those specimens. If the metabolite levels are abnormal the baby will be reported as positive for galactosemia. Screening for galactosemia using the GALT enzyme test will NOT detect the variant forms of galactosemia (galactosekinase or uridine diphosphate galactose 4 epimerase). Information on treatment centers is also available on this site. For information about other screened disorders, click on the next page button, or follow one of these links:
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