An acquired Bernard-Soulier-like platelet defect associated with juvenile myelodysplastic syndrome.

Bernard-Soulier syndrome is an inherited bleeding abnormality characterized by thrombocytopenia with large platelets and deficiency of the platelet membrane glycoprotein (GP) Ib-IX complex. We have identified a young female with an acquired Bernard-Soulier-like platelet defect and a coexisting primary myelodysplastic disorder. Abnormal bruising had developed at age 5. A normal platelet count with some giant platelets was noted at age 7. At age 9 she developed a large haematoma following surgery. Laboratory investigation revealed thrombocytopenia and large platelets. Platelet membrane glycoprotein analysis showed a marked deficiency of the components of the GP Ib-IX complex (approximately equal to 25% of normal). Flow cytometry revealed two populations of platelets: a predominant population of large platelets lacking the GP Ib-IX complex and a minor population of normal-sized platelets with normal GP Ib-IX expression. The patient developed progressive anaemia, more severe thrombocytopenia and neutropenia, and circulating blast cells were seen. A bone marrow showed gross hypercellularity with marked dysplasia of all three lineages and increased blasts. Marrow cytogenetic studies showed the presence of monosomy 7 in all metaphases, with an additional trisomy 21 in 10%. Peripheral blood cells were normal 46XX. The above data are consistent with an acquired myelodysplastic syndrome associated with a Bernard-Soulier-like platelet defect.