Marked tachypnea in siblings with chronic beryllium disease due to copper-beryllium alloy

Two biological sisters working at the same factory for > 9 years developed chronic beryllium disease (CBD) from a copper-beryllium alloy. Both had marked tachypnea (36 breaths/min and 45 breaths/min at rest, respectively), persisting over 8 years. Ventilation during exercise (assessed in one sibling) was grossly excessive (57 L/min, expected 23 L/min) with a respiratory rate of 64 breaths/min even with normal baseline routine pulmonary function tests. Blood beryllium lymphocyte transformation test and lung biopsies confirmed the diagnosis. No other cases of CBD have been reported from this plant among about 120 workers. These cases support the genetic basis for berylliosis and illustrate the marked tachypnea that may accompany this disease.