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7096969 
Journal Article 
Abstract 
Role of metallothionein 2A polymorphism on lead metabolism: Are pregnant women with a heterozygote genotype for metallothionein 2A polymorphism and their newborns at risk of having higher blood lead levels? 
Kayaalti, Z; Tekin, D; Söylemezoğlu, T 
2011 
1 
Toxicology Letters
ISSN: 0378-4274
EISSN: 1879-3169 
205 
Suppl. 
S106 
English 
WOS:000293814500336 
Numerous studies indicate that certain genetic polymorphisms modify lead toxicokinetics. Metallothioneins are protective against the toxicity of many metals, including lead. Placenta protects the fetus from certain toxicants, however, it can not prevent the fetus from exposure to lead, as this metal is able to cross the placental barrier easily. The aim of this study was to determine whether the maternal metallothionein 2A(MT2A)-5A/G single nucleotide polymorphism is related to the lead levels in maternal blood, placental tissue and the umbilical cord in 91 pregnant women and their newborns. Venous blood from the mother was collected to investigate lead levels and MT2A polymorphism. Cord blood and placenta were collected for lead levels. Analyses were made using an Atomic Absorption Graphite Furnace Spectrophotometer. Standard PCR-RFLP technique was used to determine MT2A polymorphism. Blood lead levels of heterozygote genotype mothers were statistically higher than those of homozygote genotype (p < 0.05). Maternal lead levels were significantly associated with umbilical cord lead levels for pregnant women with a homozygote genotype (p < 0.001). This association was not statistically significant for pregnant women with a heterozygote genotype. In contrast, the mean value of umbilical cord blood lead level for newborns with mothers of a heterozygote genotype was slightly higher than others but did not reach significance. No significant difference existed in placenta lead levels between both groups. This study suggests that pregnant women with a heterozygote genotype for MT2A polymorphism might have high blood lead levels and their newborns may be at risk of low-level umblical cord blood lead variation. 
47th Congress of the European Societies of Toxicology (EUROTOX) 
Paris, France 
August 28-31, 2011