A wide range of different genetic alterations are spread throughout the F9 gene, including single nucleotide substitutions, small and large deletions (Rallapalli PM et al. 2013). However functional consequences of most F9 mutations are poorly studied. The Reactome event describes altered functions of HB-associated FIX variants such as reduced FIX protein secretion due to defective expression and/or processing, failed proteolysis of factor X to Xa by defective FIX and failed formation of a membrane complex in the presence of Ca2+ ions, phospholipid, and cofactor VIIIa. The annotated HB-associated FIX variants are supported with data from functional studies (Usharani P et al. 1985; Spitzer SG et al. 1990; Ludwig M et a. 1992; Kurachi S et al. 1997; Branchini A et al. 2013).
Ludwig, M, Goossens, M, Reitsma, PH, Schwaab, R, Yoshioka, A, Poon, MC, Brownlee, GG, Green, PM, Giannelli, F, Sommer, SS
Factor VIII and Factor IX Subcommittee, -, Aledort, LM, Rosendaal, F, White, GC, Lusher, JM, Ingerslev, J, Rothschild, C
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