Mutational analysis of the GALT gene in Filipino patients

Classic galactosemia is an inherited metabolic disorder due to mutations in the galactose-1-phosphate uridyltransferase (GALT) gene. This study describes the results of the GALT gene analysis of four unrelated Filipino patients with Classic Galactosemia. DNA extracted from dried blood spots and peripheral blood of the patients, age one month to two and a half years, underwent PCR-amplification with subsequent bidirectional sequencing of all eleven exons with their flanking intronic regions following standard protocols. Clinical data of these patients were reviewed. The patients presented with jaundice, hepatomegaly, diarrhea, vomiting, poor feeding and seizures during their neonatal period. They were diagnosed with elevated blood galactose and galactose-1-phosphate and absent GALT activity. Four missense mutations were found wherein two were previously reported (p.V168L and p.A345D) and two were novel (p.L116P and p.M178R). The most frequent mutation in our cohort is p.V168L. This study suggests that GALT mutations are ethnic-specific and that galactosemia is a heterogeneous disorder at the molecular level. The importance of early detection, immediate and proper medical management and genetic counseling of the patients and their families cannot be overemphasized.