ArticleNeurotoxicology2013
Effect modification by transferrin C2 polymorphism on lead exposure, hemoglobin levels, and IQ.
Article in Neurotoxicology, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 3 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
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Who cites it
6 citing papers in PubMed, 3 syntheses or guidelines pooled it, 20 citations in OpenAlex.
- Quantifying uncertainty: a practical comparison of Bayesian and frequentist meta-analytic frameworks applied to lead exposure and children's IQ.BMC medical research methodology · 2026Pooled it
- Systemic review of genetic and epigenetic factors underlying differential toxicity to environmental lead (Pb) exposure.Environmental science and pollution research international · 2022Pooled it
- Exposure to Mixtures of Metals and Neurodevelopmental Outcomes: A Multidisciplinary Review Using an Adverse Outcome Pathway Framework.Risk analysis : an official publication of the Society for Risk Analysis · 2015Pooled it
- An Industry-Relevant Metal Mixture, Iron Status, and Reported Attention-Related Behaviors in Italian Adolescents.Environmental health perspectives · 2024Article
- Hyaluronic Acid Methacrylate Hydrogel-Modified Electrochemical Device for Adsorptive Removal of Lead(II).Biosensors · 2022Article
- Maternal iron metabolism gene variants modify umbilical cord blood lead levels by gene-environment interaction: a birth cohort study.Environmental health : a global access science source · 2014Article
Corrections and comments
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Authors and funding
9 authors at 7 institutions in 5 countries.
Funding
Abstract
backgroundIron deficiency and lead exposure remain significant public health issues in many parts of the world and are both independently associated with neurocognitive deficits. Polymorphisms in iron transport pathways have been shown to modify the absorption and toxicity of lead.
objectiveWe hypothesized that the transferrin (TF) C2 polymorphism modifies the effects of lead and hemoglobin on intelligence.
methodsChildren aged 3-7 years (N=708) were enrolled from 12 primary schools in Chennai, India. The Binet-Kamath Scale of Intelligence were administered to ascertain intelligence quotient (IQ). Venous blood was analyzed for lead and hemoglobin levels. Genotyping for the TF C2 polymorphism (rs1049296) was carried out using a MassARRAY iPLEXTM platform. Stratified analyses and interaction models, using generalized estimating equations, were examined to explore interactions between lead, hemoglobin, and TF C2 categories.
resultsA one-unit increase in log blood lead and 1g/dl higher hemoglobin was associated with -77 (95% CI: -136, -18) and 17 (95% CI 14, 21) IQ points, respectively, among children carrying the C2 variant. In comparison, among children who had the homozygous wildtype allele, the same increment of lead and hemoglobin were associated with -21(95% CI: -65, 24) and 28 (95% CI: 15, 40) IQ points, respectively. There was a significant interaction between lead (p=0.04) and hemoglobin (p=0.07) with the C2 variant.
conclusionChildren who carry the TF C2 variant may be more susceptible to the neurotoxic effects of lead exposure and less protected by higher levels of hemoglobin.
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Registered trials
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