Summary
Paris-Trousseau syndrome (PTS) is an inherited disorder char-acterized by mild hemorragic
tendency associated with 11q chromosome deletion. Here we report ten new patients
(5 boys,5 girls) with complete clinical history, biological data, ultra-structural
and molecular investigations. Thrombocytopenia is chronic in all the patients except
two boys in whom it disappeared during the two first years of life. On Romanovsky
stained peripheral blood smears, abnormal platelets with giant granules were detected
in all the children and confirmed by electron microscopy (EM). On bone marrow smears,
dysmega-karyopoiesis with many micromegakaryocytes was constantly observed. Abnormal
alpha-granules were virtually absent from bone marrow and cultured megakaryocytes,
while EM detected numerous images of granule fusion within blood platelets. Molecular
analyses evidenced that the fli-1 gene is deleted in all the patients except one confirming
the crucial role of the transcription factor FLI-1 in megakaryopoiesis. In summary,
this study documents ten new cases of PTS with characteristic alpha-granule abnormalities,
and shows the putative pathogenic role of fli-1 gene in the pathophysiology of this
syndrome.
Keywords
Paris Trousseau syndrome - giant alpha–granule - 11q 23 deletion - fli-1 gene