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

Summary 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 (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.