Spectrum of causative mutations in patients with haemophilia A in Austria

Summary

In patients with haemophilia A knowledge of the pathogenetic mutation is important i) as basis for carrier diagnosis and ii) for risk estimation of inhibitor formation. The pathogenetic mutations were identified by testing inversions in intron 1 and 22 (IVS22 and IVS1) and sequencing part of the promoter, the coding region and the exon/intron boundaries in a cohort of Austrian haemophilia A patients. A total of 239 patients from nine participating centres, who had consented to genetic testing and of whom clinical information was available were included in the study. First, IVS22 and IVS1 were tested; in case of absence of either inversion patients were subjected to sequencing. Mutations within the FVIII gene were identified in 234 patients. Notably, 53 mutations had not previously been described in HAMSTeRS. Of our patient cohort, 72.5 % had either an IVS22 or a missense mutation. Interestingly, in three brothers with severe haemophilia, we found a double mutation in exon 14 (missense + small deletion). The spectrum of mutations in Austrian haemophilia A patients was comparable to that found in the German and Italian population; however, it differed from the spectrum reported in the UK. In conclusion, 53 not previously published mutations were identified in Austrian haemophilia A patients. The occurrence of double mutations in the factor VIII gene could be confirmed and their low frequency was corroborated. We speculate that the differences between mutations in Austria and other European countries are due to ethnic diversity. Detailed investigations of the association of ethnicity and the mutation spectrum are planned.

Keywords

Austria - haemophilia - mutation analysis

^* Dr. Reitter is recipient of a Bayer Haemophilia Clinical Training Award.

^♣ See Appendix for a list of the Study Group members.

• References

• 1 Haldane JBS. The rate of spontaneous mutation of a human gene. J Genetics 1935; 31: 317-326.
• 2 White GC, Rosendaal F, Aledort LM. et al Definitions in hemophilia – Recommendation of the Scientific Subcommittee on factor VIII and factor IX of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis. Thromb Haemost 2001; 85: 560.
• 3 Bicocchi MP, Pasino M, Lanza T. et al Analysis of 18 novel mutations in the factor VIII gene. Br J Haematol 2003; 122: 810-817.
• 4 Kemball-Cook G, Tuddenham EGD, Wacey I A. The Factor VIII Structure and Mutation Resource Site: HAMSTeRS Version 4. Nucleic Acids Res 1998; 26: 216-219.
• 5 Lakich D, Kazazian HH, Antonarakis SE, Gitschier J. Inversions disrupting the factor-Viii gene are a common-cause of severe hemophilia-A. Nature Genet 1993; 05: 236-241.
• 6 Bagnall RD, Waseem N, Green PM. et al Recurrent inversion breaking intron 1 of the factor VIII gene is a frequent cause of severe hemophilia A. Blood 2002; 99: 168-174.
• 7 Green PM, Bagnall RD, Waseem NH. et al Haemophilia A mutations in the UK: results of screening one-third of the population. Br J Haematol 2008; 143: 115-128.
• 8 Green PM, Montandon AJ, Ljung R. et al Hemophilia-B Mutations in A Complete Swedish Population-Sample – A Test of New Strategy for the Genetic-Counseling of Diseases with High Mutational Heterogeneity. Br J Haematol 1991; 78: 390-397.
• 9 Higuchi M, Kazazian HH, Kasch L. et al Molecular Characterization of Severe Hemophilia-A Suggests That About Half the Mutations Are Not Within the Coding Regions and Splice Junctions of the Factor-Viii Gene. Proc Natl Acad Sci USA 1991; 88: 7405-7409.
• 10 Green PM, Bagnall RD, Waseem NH. et al Haemophilia A mutations in the UK: results of screening one-third of the population. Br J Haematol 2008; 143: 115-128.
• 11 Bagnall RD, Waseem N, Green PM. et al Recurrent inversion breaking intron 1 of the factor VIII gene is a frequent cause of severe hemophilia A. Blood 2002; 99: 168-174.
• 12 Liu Q, Nozari G, Sommer SS. Single-tube polymerase chain reaction for rapid diagnosis of the inversion hotspot of mutation in hemophilia A. Blood 1998; 92: 1458-1459.
• 13 CMGS website Sequencing Best Practice Guidelines. Available at. http://www.cmgs.org/BPGs/Best_Practice_Guidelines.htm (Accessed on 6–16–2009). Communication
• 14 Vlot AJ, Koppelman SJ, Bouma BN. et al Factor VIII and von Willebrand factor. Thromb Haemost 1998; 79: 456-465.
• 15 Sheffield Database. Available at. http://www.vwf.group.shef.ac.uk/ (Accessed on 6–16–2009).
• 16 den Dunnen JT, Antonarakis E. Nomenclature for the description of human sequence variations. Hum Genetics 2001; 109: 121-124.
• 17 Theophilus BDM, Enayat MS, Williams MD. et al Site and type of mutations in the factor VIII gene in patients and carriers of haemophilia A. Haemophilia 2001; 07: 381-391.
• 18 Haemophilia B Database. Available at. http://www.kcl.ac.uk/ip/petergreen/haemBdatabase.html (Accessed on 7–24–2009).
• 19 Oldenburg J, Ananyeva NM, Saenko EL. Molecular basis of haemophilia A. Haemophilia 2004; 10: 133-139.
• 20 Margaglione M, Castaman G, Morfini M. et al The Italian AICE-Genetics hemophilia A database: results and correlation with clinical phenotype. Haematologica 2008; 93: 722-728.
• 21 Green PM, Bagnall RD, Waseem NH. et al Haemophilia A mutations in the UK: results of screening one-third of the population. Br J Haematol 2008; 143: 115-128.
• 22 Margaglione M, Castaman G, Morfini M. et al The Italian AICE-Genetics hemophilia A database: results and correlation with clinical phenotype. Haematologica 2008; 93: 722-728.
• 23 Green PM, Bagnall RD, Waseem NH. et al Haemophilia A mutations in the UK: results of screening one-third of the population. Br J Haematol 2008; 143: 115-128.
• 24 Oldenburg J, Ananyeva NM, Saenko EL. Molecular basis of haemophilia A. Haemophilia 2004; 10: 133-139.
• 25 Margaglione M, Castaman G, Morfini M. et al The Italian AICE-Genetics hemophilia A database: results and correlation with clinical phenotype. Haematologica 2008; 93: 722-728.