Sickle Cell Trait Sickle Cell Anemia is a disease characterized by abnormal hemoglobin (oxygen carrying) molecules.  It results in anemia (see discussion under Sickle Cell Anemia). Sickle Cell Anemia occurs when a person has two genes for Hemoglobin S (the abnormal hemoglobin).  Sickle Cell Trait occurs when a person has only one gene for Hemoglobin S.  These individuals have predominantly normal hemoglobin, and only get symptoms under extreme conditions, such as high altitudes, and at times, airplane flights (since airplanes are pressurized to 5000 feet of altitude).  This disease does not shorten the life span of the patient. If two individuals with Sickle Cell Trait have children, there is a one in four chance that their offspring will develop Sickle Cell Anemia.  Sickle Cell Anemia is a very serious illness.  Couples in whom there is suspicion of Sickle Cell Trait, should have genetic counseling/testing before conceiving. Additionally, if there is Sickle Cell Anemia or a Sickle Cell Trait in the family history, this is a sufficient reason to have genetic testing, as you, the subject, may be an asymptomatic carrier of the Sickle Cell Trait. See Sickle Cell Anemia for a detailed discussion of treatment in the event Sickle Cell Trait  develops into anemia.