Advertisement
Advertisement
Advertisement

Absence of Correlation between X Chromosome Inactivation Pattern and Plasma Concentration of Factor VIII and Factor IX in Carriers of Haemophilia A and B

Journal: Thrombosis and Haemostasis
ISSN: 0340-6245
Issue: 2000: 83/3 (Mar) pp.358-519
Pages: 433-437

Absence of Correlation between X Chromosome Inactivation Pattern and Plasma Concentration of Factor VIII and Factor IX in Carriers of Haemophilia A and B

Karen Helene Ørstavik (1) , Elma Scheibel (2) , Jørgen Ingerslev (3) , Marianne Schwartz (4)
From the (1) Department of Medical Genetics, Ullevål University Hospital, Oslo, Norway; (2) Centre for Haemophilia, University Hospital Rigshospitalet, Copenhagen, (3) Centre for Haemophilia and Thrombosis, Skejby University Hospital, Århus, and (4) Se

Summary

Haemophilia A and B are X-linked disorders which are due to a reduced activity of coagulation factor VIII or IX, respectively. Female carriers have a wide range of plasma concentration of factor VIII or factor IX, and may in rare cases have an affected phenotype. In order to investigate if this variation is related to X chromosome inactivation, we determined the X inactivation pattern in 31 haemophilia A and 15 haemophilia B carriers, using a PCR in the androgen receptor locus in blood DNA. Seven of the haemophilia A carriers and none of the haemophilia B carriers had a skewed pattern (80:20). One of the skewed haemophilia A carriers had a low plasma concentration of factor VIII (0.15 U/ml), but the remaining 6 carriers did not differ in factor VIII concentration from that of carriers with a random X inactivation pattern. One carrier with a high factor VIII concentration (2.0 U/ml) did not have a skewed pattern. Similarly, for the haemophilia B carriers, there was no tendency to a more skewed X inactivation pattern in the carriers with low or high factor IX concentrations. In addition, we analysed a female with haemophilia B who was heterozygous for the mutation R180W in the factor IX gene. She had a random X chromosome inactivation pattern. We conclude that the wide range in plasma concentration of factor VIII and factor IX in haemophilia A and B carriers cannot in general be explained by the X chromosome inactivation pattern in peripheral blood cells.

Thrombosis News

Mobile technology identifies people with unknown atrial fibrillation at high risk of stroke – article published in Thrombosis and Haemostasis

The article “Feasibility and cost effectiveness of stroke prevention through community screening...

TH 111.4

The April 2014 TH 111.4 issue of Thrombosis and Haemostasis is a Theme Issue by Guest Editor B....

TH 111.3

Women with atrial fibrillation have a much higher risk for thromboembolic stroke than men suffering...