Office of Aerospace Medicine Technical Reports

FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute


Report No: DOT/FAA/AM-78/30

Title and Subtitle: Assessment of factors possibly contributing to the susceptibility of sickle trait erythrocytes to mild hypoxia: I. Design considerations and research protocol

Report Date: August 1978

Authors: McKenzie JM

Abstract: This report continues a review (see FAA-AM-76-15) of the evidence for mixed dominance of the Hbs beta gene in people with the sickle cell trait. These individuals, whose erythrocytes contain a mixture of hemoglobins (HbA/HbS), are healthy and have a normal life expectancy. They are tolerant to moderate altitudes; their erythrocytes become sickled only at oxygen tensions that would be hazardous to any person.

However, there is a possibility that other debilitating factors (e.g., alcoholism, pulmonary disorders) can, in a small fraction of those with the trait, produce an abnormal susceptibility to hypoxia. Those so debilitated would not be medically qualified to serve as air crewmembers. This report presents an experimental plan for estimating the proportion of such individuals in a population of young people with the sickle trait and outlines methods to be used in the study.

Key Words: Stress physiology, Hemoglobin, Aviation personnel, Sickle cell disease, Sickle cell trait, Medical certification

No. of Pages: 8

Last updated: Friday, June 1, 2012