SynthesisEnvironmental health perspectives2007
Lead and delta-aminolevulinic acid dehydratase polymorphism: where does it lead? A meta-analysis.
Synthesis in Environmental health perspectives, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers, 5 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
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
41 citing papers in PubMed, 5 syntheses or guidelines pooled it, 106 citations in OpenAlex.
- Toxic heavy metal exposure and heart health: a systematic review and meta-analysis of 324,331 patients.BMC cardiovascular disorders · 2025Pooled it
- Effects of the δ-aminolevulinic acid dehydratase polymorphism rs1800435 on blood lead levels: a new systematic review and meta-analysis.Scientific reports · 2025Pooled it
- Systemic review of genetic and epigenetic factors underlying differential toxicity to environmental lead (Pb) exposure.Environmental science and pollution research international · 2022Pooled it
- Genome-wide association study of blood lead shows multiple associations near ALAD.Human molecular genetics · 2015Pooled it
- Rethinking Meta-Analysis: Applications for Air Pollution Data and Beyond.Risk analysis : an official publication of the Society for Risk Analysis · 2015Pooled it
- Article
- Toward Smart Salivary Diagnostics: A Comprehensive Review of Heavy Metal Biomarkers and Digital Risk Modeling.Diagnostics (Basel, Switzerland) · 2026Review
- Exposure of Sub-adult Nile Crocodiles (Crocodylus niloticus) to Extreme Lead Concentrations: A 48-week Experimental Study with Implications for Wild Populations.Archives of environmental contamination and toxicology · 2025Article
- Epigenetic Mechanisms of Endocrine-Disrupting Chemicals in Breast Cancer and Their Impact on Dietary Intake.Journal of xenobiotics · 2024Review
- DNA damage and ALAD polymorphism in high blood lead (Pb) levels of pregnant women attending a tertiary care teaching hospital.European journal of obstetrics & gynecology and reproductive biology: X · 2024Article
- The Human Myelin Proteome and Sub-Metalloproteome Interaction Map: Relevance to Myelin-Related Neurological Diseases.Brain sciences · 2022Article
- Molecular Studies on the Nephroprotective Potential ofMolecules (Basel, Switzerland) · 2021Article
- Genetic susceptibility of δ-ALAD associated with lead (Pb) intoxication: sources of exposure, preventive measures, and treatment interventions.Environmental science and pollution research international · 2021Review
- Maternal Δ-aminolevulinic acid dehydratase 1-2 genotype enhances fetal lead exposure and increases the susceptibility to the development of cerebral palsy.Environmental science and pollution research international · 2020Article
- Blood lead level among fuel station workers, Ganesh idol painters, persons with routine daily application lead containing black pigment to eyes and Garage workers.Journal of family medicine and primary care · 2020Article
- Genotoxic Effect of Lead and Cadmium on Workers at Wastewater Plant in Iraq.Journal of environmental and public health · 2020Article
- Effects of delta-Aminolevulinic Acid Dehydratase Gene Polymorphism on Hematological Parameters and Kidney Function of Lead-exposed Workers.The international journal of occupational and environmental medicine · 2019Article
- Effects ofPlant direct · 2018Article
- Smelting Remains a Public Health Risk Nearly a Century Later: A Case Study in Pueblo, Colorado, USA.International journal of environmental research and public health · 2018Article
- Childhood Lead Exposure and Adult Neurodegenerative Disease.Journal of Alzheimer's disease : JAD · 2018Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundLead poisoning affects many organs in the body. Lead inhibits delta-aminolevulinic acid dehydratase (ALAD), an enzyme with two co-dominantly expressed alleles, ALAD1 and ALAD2.
objectiveOur meta-analysis studied the effects of the ALAD polymorphism on a) blood and bone lead levels and b) indicators of target organ toxicity. DATA SOURCE: We included studies reporting one or more of the following by individuals with genotypes ALAD1-1 and ALAD1-2/2-2: blood lead level (BLL), tibia or trabecular lead level, zinc protoporphyrin (ZPP), hemoglobin, serum creatinine, blood urea nitrogen (BUN), dimercaptosuccinic acid-chelatable lead, or blood pressure. DATA EXTRACTION: Sample sizes, means, and standard deviations were extracted for the genotype groups. DATA SYNTHESIS: There was a statistically significant association between ALAD2 carriers and higher BLL in lead-exposed workers (weighted mean differences of 1.93 microg/dL). There was no association with ALAD carrier status among environmentally exposed adults with BLLs < 10 microg/dL. ALAD2 carriers were potentially protected against adverse hemapoietic effects (ZPP and hemoglobin levels), perhaps because of decreased lead bioavailability to heme pathway enzymes.
conclusionCarriers of the ALAD2 allele had higher BLLs than those who were ALAD1 homozygous and higher hemoglobin and lower ZPP, and the latter seems to be inversely related to BLL. Effects on other organs were not well delineated, partly because of the small number of subjects studied and potential modifications caused by other proteins in target tissues or by other polymorphic genes.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.