Splenic sequestration syndrome at mountain altitudes in sickle/hemoglobin C disease.

The splenic sequestration syndrome was observed in five children with sickle/hemoglobin C (S/C) disease in association with a change in altitude. In four of them, it occurred during or immediately following a trip to mountain altitudes greater than 9,000 feet. In the fifth child, the crisis occurred in ten days after travel in a pressurized plane from sea level to Denver. No previous reports of this complication in S/C patients during mountain travel have been noted although the occurrence is known in association with aircraft flights.