Gamma heavy chain disease—An expanding clinical and laboratory spectrum

Abstract

In this review we consider the expanded clinical and laboratory spectrum of gamma heavy chain disease based on 25 reported cases, and we describe an additional patient with several unique features. These features included the youth of the patient (age 18), rapidity of his course (death occurring within five weeks of clinical onset) and bone involvement with hypercalcemia. The patient's serum and urine contained a gamma heavy chain fragment of unusually fast electrophoretic mobility belonging to the gamma G4 subclass. This gamma heavy chain protein was found to be a noncovalently linked dimer lacking interchain disulfide linkages. The structural features of other gamma heavy chain proteins were reviewed and compared with those in our case.