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Lead poisoning as a toxogenetic disease
Klinische Wochenschrift
|May 2, 1984
Summary
Two patients with lead intoxication showed persistent low red blood cell delta-aminolevulinic acid dehydratase activity. This enzyme deficiency, inherited from their mothers, suggests heterozygotes are more sensitive to lead exposure.
Area of Science:
- Biochemistry
- Toxicology
- Genetics
Background:
- Lead intoxication is a significant public health concern.
- Red blood cell delta-aminolevulinic acid dehydratase (ALAD) is a key enzyme in heme synthesis.
- ALAD activity is known to be inhibited by lead.
Observation:
- Two unrelated patients with acute lead intoxication presented with persistent reduced red blood cell ALAD activity.
- Enzyme activity remained 30%-60% lower than controls even after lead levels and heme precursors normalized.
- Subnormal ALAD activity was also observed in the mothers of both patients.
Findings:
- The persistent decrease in ALAD activity suggests an underlying inherited enzyme deficiency.
- The enzyme deficiency was confirmed in the mothers, indicating a heterozygous state.
- These individuals exhibit increased sensitivity to lead exposure due to their genetic predisposition.
Implications:
- Identifies a genetic predisposition (heterozygosity for ALAD deficiency) increasing susceptibility to lead toxicity.
- Highlights the importance of considering inherited enzyme deficiencies in cases of unusual or persistent responses to toxic exposures.
- Suggests potential for targeted screening and preventative strategies for individuals with ALAD deficiency and lead exposure risk.