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Alpha-1-antitrypsin-deficient phenotype is not maintained by segregation distortion
American Journal of Physical Anthropology
|September 1, 1983
Summary
The alpha-1-antitrypsin Z allele, linked to severe deficiency, is not preferentially transmitted. This study found no evidence of segregation distortion in families with one Z allele parent.
Area of Science:
- Genetics and Molecular Biology
- Human Population Genetics
- Protease Inhibitor Deficiency
Background:
- The alpha-1-antitrypsin (AAT) Z allele is associated with severe AAT deficiency, a condition leading to lung and liver diseases.
- Previous hypotheses suggested that the high frequency of the AAT Z allele in populations might be maintained by segregation distortion.
Purpose of the Study:
- To investigate whether segregation distortion plays a role in maintaining the relatively high gene frequency of the alpha-1-antitrypsin Z allele.
Main Methods:
- Analysis of 121 nuclear families where one parent was heterozygous for the AAT Z allele.
- Statistical correction for ascertainment bias in family selection.
- Examination of allele transmission patterns in 278 informative offspring.
Main Results:
- No evidence of preferential transmission of the AAT Z allele was detected in the studied offspring.
- Segregation distortion does not appear to be the mechanism responsible for the high frequency of the AAT Z allele.
Conclusions:
- The findings do not support the hypothesis that segregation distortion maintains the alpha-1-antitrypsin Z allele frequency.
- Alternative evolutionary mechanisms may be responsible for the observed high gene frequency of the AAT Z allele.
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