Development of a diagnostic kit for galactosemia newborns

Abstract

Galactosemia is an autosomal recessive hereditary disease associated with a violation of the conversion of galactose into glucose. Galactose is one of the main sugars present in human milk and enters the newborn’s body during the first hours of life. For this reason, early diagnosis of galactosemia is a priority. The objective of this study was to develop a technology consisting of domestic reagents for early diagnosis of galactosemia by measuring total galactose in dry blood spots (DBS). The technology is based on the enzymatic oxidation of galactose to galactonate by galactose dehydrogenase, in which NAD⁺ is reduced to NADH. The fluorescence intensity of NADH is measured, and the results are recorded. The conversion of galactose-1-phosphate, present in erythrocytes, to galactose is catalysed by the enzyme alkaline phosphatase. Regulations and instructions for the kit have been developed. The development of strains capable of producing galactose dehydrogenase and alkaline phosphatase has also been undertaken. These enzymes are capable of being stored for extended periods in lyophilized form and exhibit high activity after reconstruction in buffer solutions. The novel technology exhibits comparable precision in galactose quantification to its analogous counterparts, yet it employs an alternative reagent foundation.