RESUMEN
Bernard-Soulier's syndrome (BSS) is a familial hemorrhagic disease that is not very common, but its hemostatic defects have not been explained satisfactorily. In this paper the authors comments on the lack of Ib and Is glycoproteins in the platelet membrane, which is the basic characteristic of platelets with BSS. These proteins contain large amounts of sialic acid and have been identified as the absent membrane marker in said patients. The role played by these alterations in the BSS platelets leads us to suppose that there are no other structural and functional defects in such platelets, other than those related to the absence of membrane marker mentioned. From the above, a discussion follows on the similarity of BSS with von Willebrand's disease and it is concluded that the BSS is due to a scarce molecular concentration of Ib and Is glycoproteins in the platelet membrane and not to a functional defect of such molecules. The case described in this paper is the first one to be published in this country and was studied using the most useful and recommendable tests known at present, to this end.