Probable genetic linkage between genes coding for platelet‐specific antigens of the PI^A and bak systems

Abstract

Studies of the inheritance of the platelet-specific alloantigens PlA1/PlA2 and Baka/Bakb in informative families provided evidence that the genes determining PlA and Bak antigens are in close genetic linkage (P = .004). In 154 normal, unrelated Caucasian subjects it was found that the antigen PlA1 is associated with Baka and the antigen PlA2 with Bakb more often than would be expected by chance (P less than .05). Bak and PlA antigens are carried on platelet membrane glycoproteins IIb and IIIa, respectively, which are decreased or absent in the inherited platelet disorder Glanzmann's thrombasthenia. Thus, the findings suggest that the defect in this disease involves two closely linked genes.

Gene frequencies of human platelet antigens in the Tunisian population

“…However the occurrence of the second polymorphism associated with HPA‐1b (T→G codon 40 in GPIIIa), as described by Perichon et al ( 7), was not observed in this panel of individuals. Nor has a potential linkage desequilibrium between HPA‐1 and 3, as suggested by Letellier et al ( 9), been observed to any significant degree in this population.…”

The effect of human platelet alloantigen polymorphisms on the in vitro responsiveness to adrenaline and collagen

“…It should be noted that, apart from HPA‐1, other polymorphisms might be of clinical significance with respect to thrombogenicity (Gonzalez‐Conejero et al , 1998; Carter et al , 1999; Kroll et al , 2000). Furthermore, HPA‐1 could be in linkage disequilibrium with other gp polymorphisms, which might themselves have an effect on platelet function (Letellier et al , 1988). In this sense, platelet thrombogenicity in a given individual reflects, among other factors, the result of a multitude of underlying combinations and interactions of gp polymorphisms.…”