Pyruvate kinase deficiency and its gene mutations in newborns with jaundice in East Azerbaijan province year 2014

Background: Jaundice is a relatively common finding in newborns and deficiency of pyruvate kinase (PK) in Emden Meyerhoff pathway of glycolysis in Erythrocytes can be one of the etiologic factors in its pathogenesis. It is responsible for hereditary non-spherocytic hemolytic anemia. In this study the prevalence of PK deficiency was determined in newborns with jaundice in East Azerbaijan province, Iran.

Methods: In a five month period in 2014, among all the newborns admitted to the neonatal ward of Children's Hospital of Tabriz Medical University, those with non-conjugated hyperbilirubinemia were included in this study. Routine Lab. results were collected from hospital records. PK activity was determined by Coupled Enzyme Assay by using ELISA technique. Pyruvate kinase normal range was determined in 30 umbilical cord blood samples of healthy normal newborns. A reduction more than 60% of the mean normal value labeled as deficiency. Common PK-LR gene mutations were studied by PCR-RFLP method

Results: Two hundred neonates with indirect hyperbillirubinemia, out of a total 1750 admitted newborns were included. Lab. normal mean and range of PK activities were detected as 4.1 and 3.52-8.45 mili-unit/ml (mU/ml) respectively. In 32 out of 200 (16%) of jaundiced neonates, a decrease in PK activity was detected (mean 1.98± 0.24mU/ ml).Meanwhile only 4 out of 200 neonates (2%) were G6PD deficient. Sixteen out of 32 PK deficient patients (50%) were heterozygous for G1529A PK-LR gene mutation, while the G1168A mutation was not detected in our patients.

Conclusion: A relatively high prevalence of PK deficiency was found in our newborns with jaundice in East Azerbaijan province, Iran. So PK deficiency should be considered in the differential diagnosis of newborns with jaundice. Further detailed molecular studies are recommended.