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Female resistance to hypoxia: does it explain the sex difference in mortality rates?
1Department of Public Health, Temple University, Philadelphia, Pennsylvania, USA. magedonner@aol.com
Insights
Females exhibit a one-third lower mortality rate from respiratory events, suggesting a protective X-linked dominant allele. This genetic factor may explain sex-based differences in infant, childhood, and adult mortality.
Area of Science:
- Genetics
- Pediatrics
- Mortality Studies
Background:
- The medical literature lacks a definitive explanation for the lower overall mortality rate observed in females across all age groups.
- Existing pediatric mortality data from the CDC and WHO indicate a consistent one-third lower mortality rate in females compared to males for respiratory death causes.
Purpose of the Study:
- To investigate the underlying cause of the lower female mortality rate, particularly in cases of respiratory failure.
- To propose and explore a genetic hypothesis involving an X-linked dominant allele that confers protection against respiratory death.
Main Methods:
- Review of pediatric mortality data from the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO).
- Analysis of mortality rates for respiratory death causes, focusing on sex-based differences.
- Hypothesis formulation based on observed mortality patterns and genetic principles.
Main Results:
- A consistent one-third lower mortality rate in females compared to males was observed for respiratory death causes, even those seemingly gender-independent.
- This mortality difference is hypothesized to be linked to an X-linked dominant allele with a frequency of 1/3.
- The presence of a second X chromosome in females (XX) is proposed to provide an additional probability of protection compared to males (XY).
Conclusions:
- The study hypothesizes an X-linked dominant allele as the reason for the reduced female mortality from respiratory events.
- This allele is suggested to be unmasked during cerebral anoxia, activating a protective mechanism for brain stem respiratory neurons.
- Further research involving DNA testing of the X chromosome in infants with conditions like Sudden Infant Death Syndrome (SIDS) and Infant Respiratory Distress Syndrome (IRDS) is recommended for verification.
Abstract:
There is currently no accepted explanation in the medical literature for the lower female total mortality rate in infancy, childhood and adulthood. We review the pediatric mortality data provided by Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) and show that for causes of respiratory infant death that are apparently independent of gender (e.g., suffocation from inhalation of food or other object), there is a consistently one-third lower rate of mortality in the female than in the male. This one-third lower mortality for causes of death with a respiratory terminal event is hypothesized to be due to an X-linked dominant allele that occurs with frequency 1/3. It appears as if a second X chromosome provides the one-third extra probability of protection afforded for an XX female compared with an XY male. It is suggested that the allele's function is unmasked during transient periods of cerebral anoxia, requiring a mechanism for anaerobic oxidation to prevent the death of respiratory control neurons in the brain stem. Examples of the female one-third extra chance of resistance to hypoxia are given for causes of death in infancy, such as infant respiratory distress syndrome (IRDS) and sudden infant death syndrome (SIDS), and for causes of suffocation in childhood and asphyxiation in adulthood. DNA testing of the X chromosome of probands from causes of respiratory death, such as SIDS and IRDS, where there is a one-third lower female than male death rate, is a future direction that can verify the existence of the proposed allele.
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