scholarly journals Symptomatic form of hemophilia B in female carriers

2020 ◽  
Author(s):  
Keyword(s):  
Hemophilia B ◽  
Symptomatic Form ◽  
Female Carriers

scholarly journals Similar Pattern of Increase in FIX Levels in Female Carriers and Males with Hemophilia B Leyden

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 19-20
Author(s):  
Saad Z Ahmed ◽  
Michelle O'Rourke ◽  
Vince Jenkins ◽  
Caitriona Keenan ◽  
Irene Ellen Regan ◽  
...  
Keyword(s):  
Growth Hormone ◽  
X Chromosome ◽  
Hemophilia B ◽  
Proximal Promoter ◽  
Pronounced Increase ◽  
Serial Measurement ◽  
Number Of Patients ◽  
Female Children ◽  
Low Levels ◽  
Female Carriers

Hemophilia B is a congenital X-linked recessive bleeding disorder that occurs as a result of mutations at the long (q) arm of the X chromosome at position 27. Hemophilia B affects 1 in 30,000 males; however the incidence in Ireland is more than double the international incidence and affects 1 in 12,500 male births. Hemophilia B Leyden is a sub-type of hemophilia B first recognized in 1970 in Leyden in the Netherlands. There are more than 20 genetic mutations that result in hemophilia B Leyden. These mutations cluster at three regions within the proximal promoter region of the F9 gene including mutations in nucleotides c.-34 and c.-35 (-5 and -6 legacy numbering) in almost half the cases, mutations around nucleotide c.-49 (-20) and mutations around nucleotide c.-19 (+10). Point mutations associated with hemophilia B Leyden interfere with F9 gene transcription via binding of F9 promoter to ONECUT1 in patients with c.-35 mutation, HNF4a (hepatocyte nuclear factor 4 alpha) in patients with c.-19 mutation and C/EBPa (enhancer-binding protein alpha) in patients with c.-49 mutation. A characteristic feature of hemophilia B Leyden is progressive rise in FIX:C level from the time of puberty to reach lower normal level in young adults. This led to the widely accepted believe that the increase in FIX:C level in hemophilia B Leyden is due to the effect of the androgens surge at puberty. Androgens and anabolic steroids were used for prophylactic treatment in patients with hemophilia B Leyden in a limited number of patients. Recent evidence from animal studies using hypophysectomized hemophilia B Leyden mouse model convincingly demonstrated the pre-eminent role of growth hormone (GH) in regulating the age-dependent increase in FIX:C levels. FIX:C levels were only restored to 10% of pre-hypophysectomy levels by exogenous administration of dihydrotestosterone or oestrodiol but were restored to 80% of pre-hypophysectomy levels by exogenous administration of GH. We investigated the pattern of the increase in FIX:C in 14 male children and four female children from seven different Irish families attending the National Haemophilia Centre at Children's Health Ireland, Crumlin. The hemizygous presence of hemophilia B Leyden associated variant c.35G>A was confirmed by standard dideoxysequence analysis in all children. To evaluate the timing of increase in plasma FIX:C levels, we measured FIX:C levels using automated one stage assay. Serial measurement of FIX:C in male children with hemophilia B leyden demonstrated an increase of FIX:C from severe/moderate levels at the first year of life to mild FIX:C levels within the first 3 years of life. In all 14 male children with hemophilia B Leyden, FIX:C levels increased gradually throughout childhood with more pronounced increase in FIX:C at the time of puberty (Figure 1-A). The increase in FIX:C levels coincided with the known physiological increase in GH levels. Growth hormone level is low during infancy and increases but remains stable at low levels during early childhood, until just before puberty when GH secretion surges to the highest lifetime peak. All four female carriers of hemophilia B Leyden showed low levels of FIX:C at diagnosis associated with variable bleeding symptoms (Figure 1-B). One female child had very low FIX:C level at diagnosis in the moderate hemophilia range (0.04 iu/ml), while all other three female children had low FIX:C levels at the mild hemophilia range at diagnosis (0.13 iu/ml, 0.27 iu/ml and 0.46 iu/ml respectively). Low FIX:C level in those female carriers is likely due to skewed inactivation of the unaffected X chromosome during embryogenesis (lyonization) as no child had compound heterozygosity for the F9 gene mutation and none of the children showed clinical features of Turner syndrome or testicular feminization syndrome. Serial measurement of FIX:C levels in those symptomatic female carriers of hemophilia B Leyden showed similar gradual increase in FIX:C levels during childhood with more steep increase at puberty. Our findings further assert that gender and sex hormones has no influence in the increase of FIX:C level in hemophilia B patients. Figure 1 Disclosures Nolan: Sobi: Other: personal fees; Bayer, CSL Behring, and Sanofi.: Other: sponsorship; Sanofi: Other: PI for sponsor-(Sanofi-) led clinical trial.

Markers of Hypercoagulability in Patients with Hemophilia B Given Repeated, Large Doses of Factor IX Concentrates during and after Surgery

1994 ◽  
Vol 71 (06) ◽  
pp. 737-740 ◽  
Author(s):  
E Santagostino ◽  
P M Mannucci ◽  
A Gringeri ◽  
G Tagariello ◽  
F Baudo ◽  
...  
Keyword(s):  
High Risk ◽  
Ex Vivo ◽  
Factor Ix ◽  
Hemophilia B ◽  
Coagulation System ◽  
Prolonged Treatment ◽  
Orthopedic Procedures ◽  
Factor X ◽  
Prothrombin Complex Concentrates ◽  
Increased Risk

SummaryPurer factor IX (FIX) concentrates have been produced for the treatment of hemophilia B in the attempt to reduce the risk of thrombotic complications associated with the use of prothrombin complex concentrates. To evaluate ex vivo whether or not FIX concentrates activate the coagulation system in conditions associated with a high risk for thrombosis, we measured markers of hypercoagulability in 10 patients with hemophilia B who underwent surgery, mainly orthopedic procedures, covered by multiple concentrate infusions (40-80 U/kg/day). Postinfusion plasma levels of prothrombin fragment 1+2 and factor X activation peptide did not differ significantly from the presurgical levels, neither before nor after each concentrate dose. Therefore, it appears that prolonged treatment of patients with hemophilia B undergoing high risk surgical procedures with high doses of FIX concentrate does not cause systemic activation of coagulation. This suggests that purified FIX concentrates are preferable to prothrombin complex concentrates for conditions associated with an increased risk of thrombosis.

Low Prevalence of the Factor V Leiden Mutation Among “Severe” Hemophiliacs with a “Milder” Bleeding Diathesis

1995 ◽  
Vol 74 (05) ◽  
pp. 1255-1258 ◽  
Author(s):  
Arnaldo A Arbini ◽  
Pier Mannuccio Mannucci ◽  
Kenneth A Bauer
Keyword(s):  
Hemophilia A ◽  
Factor V Leiden ◽  
Protein S ◽  
Factor Ix ◽  
Hemophilia B ◽  
Factor V ◽  
Bleeding Diathesis ◽  
Mutation Site ◽  
Spontaneous Bleeding ◽  
Factor V Leiden Mutation

SummaryPatients with hemophilia A and B and factor levels less than 1 percent of normal bleed frequently with an average number of spontaneous bleeding episodes of 20–30 or more. However there are patients with equally low levels of factor VIII or factor IX who bleed once or twice per year or not at all. To examine whether the presence of a hereditary defect predisposing to hypercoagulability might play a role in amelio rating the hemorrhagic tendency in these so-called “mild severe” hemophiliacs, we determined the prevalence of prothrombotic defects in 17 patients with hemophilia A and four patients with hemophilia B selected from 295 and 76 individuals with these disorders, respectively, followed at a large Italian hemophilia center. We tested for the presence of the Factor V Leiden mutation by PCR-amplifying a fragment of the factor V gene which contains the mutation site and then digesting the product with the restriction enzyme Mnll. None of the patients with hemophilia A and only one patient with hemophilia B was heterozygous for Factor V Leiden. None of the 21 patients had hereditary deficiencies of antithrombin III, protein C, or protein S. Our results indicate that the milder bleeding diathesis that is occasionally seen among Italian hemophiliacs with factor levels that are less than 1 percent cannot be explained by the concomitant expression of a known prothrombotic defect.

Prevalence of Inhibitors in a Population of 3435 Hemophilia Patients in France

1992 ◽  
Vol 67 (06) ◽  
pp. 600-602 ◽  
Author(s):  
Y Sultan ◽  
Keyword(s):  
Hemophilia A ◽  
Hemophilia B ◽  
Study Group ◽  
Cooperative Study ◽  
Population Prevalence ◽  
French Study ◽  
Number Of Patients ◽  
High Incidence ◽  
Recombinant Fviii ◽  
High Responders

SummaryA cooperative study between the 37 centers of the French Hemophilia Study Group was undertaken to establish the prevalence of inhibitor patients in the French hemophilia population. The prevalence reported in the literature varies widely from 3.6% to 17.5%. Some of the studies are dealing with a small number of patients and inhibitor patients are reported either to the total number of hemophiliacs or to the severely affected ones. The French study provided information concerning 3,435 hemophiliacs and showed a prevalence of 6.2% for the overall population. Prevalence of inhibitors was found to be 7% in the population of hemophilia A patients and 12.8% in the population of severely affected ones. The prevalence of inhibitors in the population of hemophilia B patients was 2% and 4% in the population of severely affected hemophilia B patients. The cooperative study also showed that 47.5% of inhibitors are detected before 10 years of age and that 82% of inhibitor patients are high responders. Analysis of inhibitor detection in patients under the age often showed that there was a peak in the population of 2 years old children. Although not comparable to the present study the high incidence of inhibitors with ultrapurified and recombinant FVIII reported in previously untransfused patient may be borne in mind.

β-Propiolactone UV Inactivated Clotting Factor Concentrate Is the Source of HIV-Infection of 8 Hemophilia B Patients: Confirmed

1995 ◽  
Vol 74 (05) ◽  
pp. 1386-1387 ◽  
Author(s):  
B Kupfer ◽  
J Oldenburg ◽  
H H Brackmann ◽  
B Matz ◽  
K E Schneweis ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Hemophilia B ◽  
Clotting Factor ◽  
Factor Concentrate

Laboratory Detection of Female Carriers of Canine Hemophilia

1964 ◽  
Vol 12 (02) ◽  
pp. 368-376 ◽  
Author(s):  
B. J Parks ◽  
K. M Brinkhous ◽  
P. F Harris ◽  
G. D Penick
Keyword(s):  
Factor Viii ◽  
Partial Thromboplastin Time ◽  
Screening Test ◽  
Factor Viii Level ◽  
Viii Level ◽  
Antihemophilic Factor ◽  
Female Carriers

SummaryFemales known to be heterozygous for canine hemophilia had a plasma antihemophilic factor (AHF, factor VIII) level of about 50%, as determined by bioassay and by the effectiveness of their transfused plasma in raising the AHF levels of hemophilic dogs. Determination of the plasma AHF should serve to identify transmitter females prior to appearance of affected progeny in litters. Lyon’s hypothesis appears to apply to our findings.The simple partial thromboplastin time (PTT) test was prolonged in heterozygous females. Modifications of the test, by the addition of thrombin, a serum accelerator preparation, or kaolin, gave consistently longer PTT values for heterozygotes than for normal dogs. The PTT appears useful as a screening test for carriers of canine hemophilia.

Extravascular Administration of Factor IX: Potential for Replacement Therapy of Canine and Human Hemophilia B

1997 ◽  
Vol 77 (05) ◽  
pp. 0944-0948 ◽  
Author(s):  
Darla Liles ◽  
Charles N Landen ◽  
Dougald M Monroe ◽  
Celeste M Lindley ◽  
Marjorie s Read ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Vitamin K ◽  
Absorption Rate ◽  
Venous Access ◽  
Factor Ix ◽  
Hemophilia B ◽  
Current Therapy ◽  
Home Therapy ◽  
Routes Of Administration ◽  
Plasma Compartment

SummaryCurrent therapy for hemophilia B requires large intravenous doses of factor IX (F.IX) given in the clinic or at home. Although home therapy is possible for many patients, it is often complicated by factors such as the lack of good venous access. Very little is known about extravascular routes for administering proteins like F.IX (57 kD) or other vitamin K-dependent procoagulant factors into the circulation. Questions about the absorption rate from extravascular administration as well as plasma recovery and bioavailability have arisen recently with the growing availibility of highly purified procoagulant proteins and increased interest in gene therapy of hemophilia B. Therefore, a group of studies were undertaken to determine the absorption rate, plasma recovery, and bioavailability of high purity, human plasma-derived F.IX concentrates administered via extravascular routes in hemophilia B dogs and in one human hemophilia B subject. Five hemophilia B dogs were given human F.IX via either a subcutaneous (SC), intramuscular (IM), intra- peritoneal (IP) or intravenous (IV) route. In a subsequent study, a single SC administration of human F.IX was compared to an identical IV dose of F.IX in the human hemophilia B subject. All extravascular routes of F.IX administration in both the canine and human gave lower levels of circulating plasma F.IX than the IV route, however all routes resulted in measurable F.IX activity. Of the extravascular routes, the IM injection in the canine resulted in a bioavailibility of 82.8%, while the SC injection resulted in a bioavailability of 63.5%. F.IX reached the plasma compartment by all extravascular routes used, confirming that F.IX can be absorbed extravascularly. The duration of measurable F.IX activity following extravascular administration is prolonged beyond that typically seen with IV administration. These data show that significant levels of F.IX may be obtained via SC injection in canine and ‘ human hemophilia B subjects and further highlight the potential of extravascular routes of administration for future experimental and clinical uses of F.IX and other procoagulant proteins.

Sign in / Sign up

Export Citation Format

Share Document