Association between a Polymorphism of Aminolevulinate Dehydrogenase (ALAD) Gene and Blood Lead Levels in Japanese Subjects

Koichi Miyaki,Htay Lwin,Katsunori Masaki,Takeo Nakayama,Yoshimitsu Takahashi,Yixuan Song,Masaaki Muramatsu

doi:10.3390/ijerph6030999

Abstract

This cross-sectional study investigated the relationship between the aminolevulinate dehydrogenase (ALAD) genotype and blood lead levels among 101 Japanese workers. Blood lead concentration measurement, biomarkers, and genotyping were performed. The minor allele frequency (MAF) for ALAD (ALAD2) was 0.08. Although the blood lead level in the subjects with heterozygous GC genotype was significantly higher than those with homozygous GG genotype, there were no significant differences for hemoglobin, hematocrit, serum and urinary ALA levels among genotypes. ALAD2 genotype was significantly associated with the blood lead concentration, even in the environmental lead exposed subjects. Further confirmation with a large sample size is needed.

Highlights

From the public health point of view, inorganic lead exposure has been a serious problem, in the occupational and in environmental settings [1]
The objective of this study examined the relationship between ALAD1, ALAD2 genotypes and blood lead level among workers who were not occupationally exposed to lead
Many previous studies have shown that the ALAD genotype was associated with blood lead levels among environmentally exposed children and occupationally exposed lead workers [16,17]

Summary

Introduction

From the public health point of view, inorganic lead exposure has been a serious problem, in the occupational and in environmental settings [1]. Estimation of the health risks associated with low-level exposures to lead has important implications with respect to its regulation. Health-based guidelines limiting occupational and environmental exposures to lead have become more stringent and are thought to protect most of population against major adverse health effects. Many reports have suggested that the ALAD2 allele may exert protective measures against the neurotoxic effects of lead [12,13,14,15]. The subjects of these reports have typically been occupationally exposed workers, and no firm evidence exists for an association between ALAD genotype and susceptibility to lead toxicity under environmental exposure levels. The objective of this study examined the relationship between ALAD1, ALAD2 genotypes and blood lead level among workers who were not occupationally exposed to lead

Subjects

Basic Characteristics and Blood Measurements

Genotyping

Statistical Analysis

Results and Discussion

Conclusions