Hereditary Thrombocytopenias in Childhood

Abstract

Thrombocytopenia is generally known in its most severe form as acquired immunologic disease. However, in some cases thrombocytopenia is constitutional and may or may not be associated with thrombocytopathy. This review focuses on the clinical and biologic diagnostic criteria of genetic thrombocytopenia, with specific emphasis on the clinical value of the platelet life span and wishes to reiterate the necessity of their identification, as an excessively rapid diagnosis of ITP may be a source of treatment failure. As an example of constitutional thrombocytopenia, we report here 83 familial cases with pure genetic macrothrombocytopenia. They are characterized by the absence of significant bleeding disorders, stable thrombocyte counts higher than 50 x 10(9)/l, platelet macrocytosis, normal platelet function, normal or never increased presence of megakaryocytes, and rarely positive immunological abnormalities. In all cases, platelet life span clearly indicated a defect of production with destruction linked to the ageing population (more than 7 days) and no abnormal sequestration in the spleen or liver. Thus, apart from thrombocytopenia with thrombocytopathy, kinetic studies are necessary in thrombocytopenias whenever clinical parameters do not suggest the presence of excessive platelet destruction.

Maternal thrombocytopenia at term: a population‐based study

“…The high specificity of the MAIPA test at 90% was to be expected from previous reports, too, but the specificity of the PIFT at 88% was surprising and suggested that both tests are useful in the diagnosis of ITP during pregnancy. Although not part of this study, certain familiar thrombocytopenias such as type IIb von Willebrandt disease, Bernard Soulier syndrome and benign autosomal dominant thrombocytopenia are generally underestimated, and need to be specially investigated if there is no response to corticosteroid or IVIG treatment of suspected ITP (16)(17).…”

Generation and rescue of a murine model of platelet dysfunction: The Bernard-Soulier syndrome

“…Whether other aspects of the Bernard-Soulier syndrome, such as the macrothrombocytopenia, are a direct result of an absent GP Ib-IX-V receptor has not been established. Indeed, there are a number of seemingly unrelated macrothrombocytopenic disorders not associated with a dysfunctional GP Ib-IX-V receptor and their molecular basis has remained unresolved (10)(11)(12)(13).…”

Hereditary giant platelet disorder presented as pseudothrombocytopenia

“…In some cases macrothrombocytopenias have been associated with Alport's syndrome (1). However, a significant number of giant platelet disorders remains without an accurate diagnosis because of the absence of specific findings (1–3).…”

“…To our knowledge, giant platelet disorders are always accompanied by thrombocytopenia (1–3). In our cases a normal platelet count was found in several microscopic examinations of peripheral blood smears, but mild/severe thrombocytopenia was diagnosed when the count was performed with haematological analysers.…”