title: Association between δ-aminolevulinate dehydratase G177C polymorphism and blood lead levels in brain tumor patients.
abstract: As the δ-aminolevulinic acid dehydratase (ALAD) G177C polymorphism affects the toxicokinetics of lead in the body, and the corresponding exposure to lead may increase the risk of adult brain tumors, we hypothesize that there is a possible association of theALADG177C genotype and the risk of brain tumors in human. Therefore, the aim of the present study was to clarify the role of the ALAD enzyme gene polymorphism at position G177C in the pathogenesis of brain tumors and its correlation to lead exposure. TheALADgene polymorphism at position G177C was genotyped using the polymerase chain reaction with restriction fragment length polymorphism method and measured the blood lead level by atomic absorption in 81 brain tumor patients and compared the results with 81 controls. The frequency of the GC genotype (ALAD1-2) was significantly increased in primary brain tumor patients compared to the control group. The genotype frequency ofALAD2 (ALAD1-2andALAD2-2) was significantly higher in the meningioma patients but was not significant in glioma patients. There was no significant difference in the number of patients and blood lead level when compared with the control. There was a significant increase when compared toALAD1regarding a mean value of the lead level. The genotyping of theALADG177C polymorphism in the present study revealed a significant association betweenALAD2and brain tumors. TheALAD G177Cpolymorphism may modify the lead kinetics in the blood, is associated with higher blood lead burden and may provide a biomarker of neurotoxic risk.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Zagazig University, Zagazig 44512, Egypt.
authors.forename: Mahmoud Mostafa
authors.initials: MM
authors.lastname: Taha
authors.affiliation: Department of Medical Biochemistry, Faculty of Medicine, Zagazig University, Zagazig 44512, Egypt.
authors.forename: Osama Abd El Aziz
authors.initials: OA
authors.lastname: Gaber
authors.affiliation: Department of Medical Biochemistry, Faculty of Medicine, Zagazig University, Zagazig 44512, Egypt.
authors.forename: Norhan Abdalla
authors.initials: NA
authors.lastname: Sabbah
authors.affiliation: Department of Medical Biochemistry, Faculty of Medicine, Al-Azhar University, Assiut 71511, Egypt.
authors.forename: Abd Allah S
authors.initials: AA
authors.lastname: Abd Elazem
keywords: brain tumor; lead; meningioma; polymorphism; δ-aminolevulinic acid dehydratase gene