3 Factor IX

Haemophilia A and haemophilia B: molecular insights

“…51 72 73 Once again, these observations may be explained by the involvement of (RY)n sequences in homologous recombination. Source references: white data, 26 Japanese data, 69 70 Chinese data, 34 71 72 American black data. 34 72-74 "As seen for polymorphisms in the factor VIII gene, factor IX gene polymorphisms show ethnic variation, which in some instances is quite pronounced"…”

Haemophilia A and haemophilia B: molecular insights

“…68 In this light, it is interesting to note that the BamHI RFLP which is 5′ to the intron 1 (RY)n is in linkage equilibrium with polymorphisms located between this (RY)n and the exon 8 (RY)n. 68 Similarly, the HhaI RFLP 3′ to the exon 8 (RY)n is in linkage equilibrium with polymorphisms between this (RY)n and the intron 1 (RY)n. 68 In contrast, the polymorphisms between the intron 1 and exon 8 (RY)n are in strong linkage disequilibrium. 26 50 72 If the (RY)n sequences of the factor IX gene truly are involved in homologous recombination events, this has evident implications for linkage studies (the loss of linkage between polymorphic loci and the defect in the factor IX gene). However, this has not been seen, although the possibility of its occurrence argues for the inclusion of several loci across the factor IX gene in a linkage study.…”

“…In whites, the TaqI, XmnI, MspI, and MnlI RFLPs show pronounced linkage disequilibrium, such that the use of all four loci would only increase informativity to 55% compared with 45% when using the TaqI site alone. 26 50 72 The DdeI and HhaI polymorphisms, however, show much less disequilibrium, 72 possibly for the reasons discussed above.…”

“…Source references: white data, 26 Japanese data, 69 70 Chinese data, 34 71 72 American black data. 34 72-74 For most of the polymorphic loci in both genes this is a straightforward task and is the mainstream approach in linkage analyses.…”

Single nucleotide polymorphisms of the factor IX gene for linkage analysis in the southern Chinese population

“…Caucasian* (n 55) American Blacks² (n 48) Chinese³, § (n 49) (n 139) Japanese ¶ (n 50) Malay** (n 52) Thai²² (n 104) Giannelli (1989 …”