RESUMEN
This study is the first to report a familial case involving differing clinical courses of aplastic crisis triggered by parvovirus B19 in two patients with HS, although similar eosin-5-maleimide-binding test and sodium dodecylsulfate-polyacrylamide gel electrophoresis results had been obtained for both. One patient had short-term mild symptoms, whereas the other patient developed severe anemia that required blood transfusion, experienced fever for 13 days, and did not have any rash. The severity of aplastic crisis is reported to be correlated with the severity of the underlying hemolytic anemia; the present findings show that the severity of infection should also be considered as an important predictive factor of the severity of aplastic crisis.