Further studies of a metabolic stress test in Wiskott-Aldrich syndrome carriers

We recently described a test using epinephrine-induced aggregation of platelets pretreated with the metabolic inhibitor 2-deoxy-d-glucose to detect carriers of the Wiskott-Aldrich syndrome (WAS). We have evaluated this test further to include 22 obligate and 16 probable carriers of the WAS gene. The optimum concentration of epinephrine to discriminate between carriers and female controls was 5.5 µM. However, even at this level there were 18% false positive results in controls and 30% false negative results in obligate carriers. A significant trend existed for all obligate carriers within a family to be either positive or negative, suggesting the test may be useful but only in certain families. Based on the present results, and recent evidence linking monoamine oxidase activity and epinephrine aggregation, we present further suggestions for improving this stress test.