Sickle cell trait and aviation.

Abstract

Sickle cell trait is a benign genetic abnormality which has been wrongly projected as a health hazard in aviation. Conflicting reports on the relationship between this trait and flying exist in the literature. Limitations placed on sickle trait individuals unfairly stigmatize large numbers of people, both socially and economically. The imprecise identification of the sickle hemoglobinopathies and unrecognized interactions of other abnormal hemoglobins with hemoglobin S have perpetuated the controversy. There is a tendency to use isolated anecdotal incidents as evidence of increased morbidity in sickle cell trait; however, it has not been documented that hypoxic conditions cause in vivo sickling in pure trait carriers. An analysis of the definitions of the hemoglobinopathies, the molecular basis of hemoglobin S, the interactions of abnormal hemoglobins, and the sickling phenomenon shows both that there is no evidence that the sickle trait is a health hazard and that most of the literature contrary to this finding is invalid.