Analysis of common mutation for GALT gene in newborns with galacatosemia Nineveh governorate

Abstract

Iraq contains many diseases that have never been counted or examined, including diseases related to food, which has deteriorated in recent years, and has rapid and direct impact especially on the children category, one of these diseases is galactosemia. Classical galactosemia, deficiency of galac tose-1-phosphate uridyltransferase GALT, is characterized by acute symptoms of hepatomegaly, jaundice, sepsis, cataract, vomiting, and diarrhea and growth retardation. Our previous molecular study showed that the most common mutation of the GALT gene is a missense mutation of Q188R (replacement of glutamine-188 by arginine in exon 6 and N314D mutation replacement of aspargen-314 by aspartic acid) in exon 10. The aim of this study was to determine the possibility of diagnosing galacatosemia, and to search for galactosemia mutation Q188R and N314D in Iraqi population. Blood samples were collected from babies admitted to the children's hospitals in Mosul City depending on the clinical symptoms of disease and then serum was taken. Measuring the Galactose-1-Phosphate uridylytransferase GALT enzyme activity and galactose -1- phosphate in serum by ELISA technique was done. DNA samples were analyzed by the polymerase chain reaction followed by digestion with restriction endonuclease HpaΙΙ and AvaΙΙ for Q188R and N314D mutation. The results showed a significant decrease in the level of the GALT enzyme in children with galactosemia 21.7 ± 0.45 and among non-diagnosed children 79.93 ± 1.44 compared with control group 160.33 ± 0.93 as well as a significant decrease in the level of the enzyme among mothers 20.5 ± 1.92 was observed. Gal-1-P level was significantly higher in the cases than that of the control group, while that of the not diagnosed children and mothers groups showed inconsistent difference. Also the result showed absence allele frequency for Q188R mutation and present allele frequency for N314D mutation in Iraqi population. In conclusions It is possible to depend on measurement of Galactose-1-Phosphate as indicator in the diagnosis of Galactosemia in newborn, the main mutation in GALT gene causes galactosemia is N314D in Iraqi population.