|
Medical
Articles
Sustained
Engraftment Post Bone Marrow Transplant Despite Anti-Platelet
Antibodies in Glanzmann Thrombasthenia
Veronica M. Flood, MD., F. Leonard Johnson, MD, Lynn K.
Boshkov, MD, Gregory A Thomas, MD, Diane J. Nugent, MD,
Antony C. Bakke, PhD, H. Stacy Nicholson, MD, MPH, David
Tilford, MD, Mary P. Brown, MD, and Kamar T. Godder, MD,
MPH.
|
| Background.
Patients with Glanzmann thrombasthenia (GT)
have normal platelet counts but abnormal platelet
aggregation and carry the risk of life-threatening
bleeding. We report three patients who received
bone marrow transplantation (BMT) for type 1
GT and discuss the risk and management of anti-platelet
antibodies. Patients and Results.
Diagnosis of GT was made through abnormal platelet
aggregation studies or the absence of GPIIb/IIIa
by flow cytometry. All patients had severe bleeding
requiring multiple red blood cell transfusions.
One patient received an unrelated donor transplant
and two received matched sibling donor transplants
following conditioning therapy with busulfan,
cyclophosphamide, and fludarabine. Two patients
developed an anti-platelet antibody, treated
in one with intravenous immune |
|
globulin
(IVIG). Engraftment of white blood cells and
platelets was achieved on day +13 to +14 and
+17 to +25, respectively. Complete donor chimerism
and GPIIb/IIIa+ platelets are sustained at
+22 to +30 months post transplant. Conclusions.
In summary, patients with GT and history of
severe hemorrhage can be cured with BMT, but
the presence of anti-platelet antibodies should
be sought and platelet transfusions minimized
prior to transplant. IVIG may be helpful in
cases of refractory immune thrombocytopenia
related to anti-platelet antibodies. Improvement
in transplant-related complications with current
transplant regimens allows consideration of
BMT for life-threatening non-malignant disorders
such as GT.
Pediatric
Blood Cancer 2005; 45;971-975. |
|
|
INTRODUCTION
Glanzmann
thrombasthenia (GT) is an inherited bleeding disorder
resulting from either qualitative or quantitative abnormalities
in the glycoprotein IIb/IIIa complex located on the platelet
membrane. Glanzmann first reported a series of patients
with muco-cutaneous bleeding, normal platelet counts,
and prolonged bleeding times in 1918. Later, it was discovered
that these patients lacked functional GPIIb/IIIa on their
platelets. This defect prevents adequate formation of
the platelet plug, which then leads to increased bleeding
at sites of injury. GT patients can be classified as type
I, with less than 5% GPIIb/IIIu and absent clot retraction;
or type II. with 10-20% GPIIb/IIIa and minimal clot retraction.
Qualitative defects manifest as variants with abnormal
function despite normal or near-normal levels of GPIIb/IIIa.
The clinical spectrum of GT is variable, with symptoms
ranging from minimal bleeding to significant epistaxis,
menorrhagia, and life-threatening hemorrhage. Treatment
typically consists of local control measures. Systemic
and topical antifibrinolytic therapy may be helpful, while
platelet transfusions are reserved for severe bleeding.
Although, the infusion of normal donor platelets will
initially allow hemostasis, GT patients may develop |
|
antiplatelet
antibodies against the GPIIb/IIIa complex, decreasing
the efficacy of transfusion and creating the risk of poor
response to future transfusions. While aiding in temporary
hemostasis, none of the measures described above address
the underlying defect. The only curative treatment to
date has been bone marrow transplantation (BMT). Four
previous transplants for GT have been reported, all with
matched sibling donors.
We report three patients who received BMT for GT at our
institution. All patients had type I GT and had experienced
severe bleeding requiring multiple transfusions. One patient
received a transplant from a human
1
Pediatric Stem cell Transplant Program. Division of Pediatric
Hematology/Oncology. Oregon Health & Science University,
Portland, Oregon
2
Department of Pathology. Oregon Heath& Science University,
Portland, Oregon
Division
of Hematology, Children's Hospital of Orange County, Orange
California
3
Central Oregon Pediatrics, Bend. Oregon
4
Correspondence to: Victoria H. Flood. Kamar T Godder,
Division of Pediatric Hematology / Oncology, DCRCP, Oregon
Health and Science University. 3181 SW Sam Jackson Park
Road, Portland, OR 97239 |
Disease type: Platelet Disorder
Chromosome: 17
Pathology
Glanzmann Thrombasthenia (GT) is a disorder affecting platelets,
and blood clotting. In GT, platelets fail to aggregate following
stimulation, failing to form blood clots. GT is an autosomal
recessive disorder in one of two genes, either the GPIIb or
GPIIIa (GP stands for glycoprotein) In GT one or both of these
proteins are mutated in some manner.
GPIIb,
and GPIIIa exist together as a dimer (they are joined together,
reffered to as: GPIIb/IIIa). GPIIb/IIIa once activated will
bind to one end of fibrinogen. Another platelet, with its
own GPIIb/IIIa can then bind to the other end of the fibrinogen.
This allows the formation of a large collection or aggregation
of bound platelets, commonly called a blood clot. In GT the
GPIIb/IIIa is defective, the platelets can no longer bind
with one another, and the blood clot fails to form.
Aetiology
The genetics underpinning the disease are very diverse,ranging
from major deletions in the gene to single point mutations.
The disease is very rare, with only about 200 cases
in the world (1995), of which only twelve have been
solved at the genetic level. Defects seem split equally
between GPIIb, and GPIIIa.
Symptoms
Common symptoms include:
Excessive bleeding after skin damage (dentist, surgery,
accidents).
Spontaneuos bleeding within the joints.
Spontaneuos bleeding within mucosal tissues.
Mennorhagia - Bleeding more severe during menstruation.
|
 |
Further reading: Newman P.J., Poncz M (1995) Inherited disoreders
of platelets. IN Scriver C.R., Beaudet A.L., William S.S.,
editors, Molecular and Metabolic basis of disease. McGraw
& Hill Inc, 3335-3358
Glanzmann's
Thrombasthenia
Dr. Mark Shumate
Glanzmann's
Thrombasthenia is a rare genetic bleeding disorder. It is
a disorder of platelet function and is caused by a deficiency
or abnormality in the membrane glycoprotein (GP) IIb-IIIa
which is responsible for the formation of a plug (haemostatic
plug) which prevents further bleeding of injured blood vessels.
In effect the platelets do not stick together adequately causing
prolonged bleeding even from minor injuries. Despite the abnormality
of platelet function, the total platelet count is normal and
specialised platelet function tests are necessary to make
the diagnosis.
Glanzmann's
Thrombasthenia may be of variable severity. Some patients
(Type 1) are severely affected whilst others are less so (Type
2). The genes for glycoprotein IIb and IIIa are on chromosome
17, but many genetic mutations have already been described.
Glanzmann's Thrombasthenia is not always the result of the
same mutation.
Normal
handling of infants can cause superficial bruises. Epistaxis
(nose bleeds) in childhood and menstrual bleeding can cause
problems.
Platelet
transfusions can be used in cases of serious bleeding. However
antibodies against platelets can develop as a result of such
transfusions. Anti-platelet drugs such as aspirin should be
avoided.
Bone marrow
transplantation is the only curative form of treatment. However
this is generally considered more hazardous than the condition
except in exceptional circumstances.
Inheritance
patterns
Autosomal recessive, carriers can now be detected.
Pre-natal
diagnosis
This is possible at 18 plus weeks through a fetal blood sample.
However where the child is affected the fetal sampling carries
a high risk of haemorrhage and may be fatal. Unaffected or
carrier fetuses will not undergo any special risk from the
testing. Genetic counselling is available.
Medical
text last updated August 2001 by Dr R F Stevens, Consultant
Haematologist/Oncologist, Royal Manchester Children's Hospital,
Manchester, UK.
GLANZMANN'S
THROMBASTHENIA CONTACT GROUP
Marilyn Buxton Glanzmann's Thrombasthenia Contact Group 28
Duke Road Newton Hyde
SK14 4JB Tel 0161 368 0219 e-mail: glanzmannsupport@btopenworld.com
This is a Contact Group founded in 1990.
Authored
by Mark J. Shumate, M.D., M.P.H., Assistant
Professor, Hematology/Oncology Division, Emory University
Edited
by Christopher D. Hillyer, M.D., Program
Director, Transfusion Medicine and Hospital Blood Bank, Associate
Professor, Departments of Medicine and Pathology, Emory University
School of Medicine; F. Talavera, Pharm.D., Ph.D.,
Department of Pharmacy, Creighton University; Emmanuel
C. Besa, M.D., Professor, Department of Medicine,
Section of Hematology and Oncology, Medical College of Pennsylvania
Hospital, MCP Hahnemann University; Rajalaxmi McKenna,
M.D., Director, Hemophilia Center; Division of Hematology,
Clinical Professor of Medicine, Hematology/Oncology Faculty
Foundation, Director, Cardeza Special Hematology and Hemostasis
Laboratories, Thomas Jefferson University and Hospital; and
Michael E. Zevitz, M.D., Director of Echocardiography
Lab, Division of Cardiology, Clinical Assistant Professor,
Department of Medicine, Finch University of Health Science/The
Chicago Medical School
Background:
Glanzmann
Thrombasthenia is a genetic platelet disorder in which the
platelet glycoprotein IIb/IIIa (GP IIb/IIIa) complex is either
deficient or present but dysfunctional. This defect leads
to defective platelet aggregation and subsequent bleeding.
It is rare and is inherited in an autosomal recessive pattern.
Pathophysiology:
Platelet
aggregation at sites of vascular injury requires expression
of GPIIb/IIIa complex on the surface of the platelets forming
the platelet plug.
GPIIb/IIIa
complex binds fibrinogen and/or von Willebrand factor (vWF).
Adjacent platelets are cross-linked through GPIIb/IIIa - fibrinogen
- GPIIb/IIIa complexes. When GPIIb/IIIa complex functions
abnormally, platelet aggregation is impaired and bleeding
occurs.
GPIIb/IIIa
complex is a heterodimer that requires calcium for the GPIIb
and GPIIIa to associate normally. Both GPIIb and GPIIIa are
required for normal platelet function. A defect in either
one can lead to a bleeding disorder.
Platelet
counts and platelet functions that do not depend on GPIIb/IIIa
are normal in thrombasthenic patients.
Frequency:
Mortality/Morbidity:
Bleeding
problems can be severe, but the prognosis remains good if
platelet transfusion is available.
Age:
Thrombasthenia
typically presents with mucocutaneous bleeding at birth or
early in infancy.
History:
- Bleeding
from a condition which could cause bleeding in an otherwise
normal individual.
- Petechiae
and ecchymoses, although spontaneous petechiae are uncommon
- Menorrhagia,
often worse at menarche
- Gingival
bleeding worse with poor dental hygiene
- Epistaxis
- Hemarthroses
are rare.
Physical:
Examine
the skin and oral mucosa for petechiae, ecchymoses and any
current bleeding.
Causes:
The disease
is a genetic condition.
Other
Problems to be Considered:
Afibrinogenemia
Autoantibodies to GPIIa/IIIb
Bernard-Soulier Syndrome and Other Qualitative Platelet Disorders
such as Gray Platelet Syndrome; Wiskott-Aldrich Syndrome;
Platelet-Type von Willebrand Disease; or Platelet Storage
Pool Defects.
Lab
Studies:
- Complete
blood count, prothrombin time and partial thromboplastin
time
- The
platelet count and other coagulation tests should be normal.
- Bleeding
times should be prolonged
- Platelet
aggregation studies
- The
primary platelet aggregation response to platelet agonists
such as ADP and epinephrine are decreased while the response
to ristocetin is normal. If the secondary platelet aggregation
response is abnormal, suspect a platelet storage pool
defect or an abnormality in platelet signal transduction
Histologic
Findings:
Platelet
morphology on peripheral blood smears is normal
Medical
Care:
- Thrombasthenia
patients who are bleeding require platelet transfusion.
- Because
patients are likely to require multiple transfusions during
their lifetime, take care to avoid platelet alloimmunization.
- Prevention
is best accomplished by using leukocyte-depleted blood
products. Leukocyte depletion can be accomplished with
mechanical filtration. Only filtered blood products should
be given.
- Use
of HLA-matched platelets is a further attempt in the prevention
of platelet alloimmunization.
- Patients
should be vaccinated for hepatitis B, due to infectious
risks associated with multiple transfusions,
- Avoid
medications that effect platelet function, such as aspirin
and other NSAIDs.
- Consider
oral contraceptives to control menorrhagia.
Surgical
Care:
- To
prevent excessive bleeding during surgery, platelets should
be transfused pre-operatively.
- Further
platelet transfusions based on maintaining hemostasis
Consultations:
A hematologist
confirms the diagnosis and makes transfusion recommendations.
Further
Outpatient Care:
- Regular
dental care is recommended to avoid gingival bleeding.
Deterrence/Prevention:
- Avoid
drugs which decrease platelet function or coagulation such
as the following:
- Aspirin
or other NSAIDs
- Heparin
- Warfarin
- Ticlopidine
or Clopidogrel
- GP
IIb/IIIa antagonists such as abciximab
- Streptokinase,
urokinase or tissue plasminogen activator
- Volume
expanders such as dextran or hydroxyethyl starch
- Dipyridamole
Complications:
- Bleeding
complications of any type
Prognosis:
- With
platelet transfusions for bleeding complications, the prognosis
is generally good.
Patient
Education:
- Regular
dental care is necessary to avoid gingivitis and gingival
bleeding.
CME
Question 1: What is the inheritance pattern of Glanzmann
thrombasthenia?
A: Autosomal dominant
B: X-linked recessive
C: Autosomal recessive
D: Y-linked dominant
E: Glanzmann thrombasthenia is not a heritable
disease
The correct answer is C: Glanzmann thrombasthenia is
due to defects in GPIIb or GPIIIa. Both of these protein`s
genes are on chromosome 17. Fifty percent activity of each
protein is enough to support normal platelet aggregation.
Therefore, the disease is inherited as an autosomal recessive
trait.
CME
Question 2: Which of the following drugs can be safely
given to a patient with thrombasthenia?
A:
Aspirin
B: Ticlopidine
C: Heparin
D: Dipyridamole
E: Gentamicin
The
correct answer is E: Aminoglycoside antibiotics such as
gentamicin do not alter platelet function, all of the other
drugs listed alter platelet function.
Pearl
Question 1: What are the results of a complete blood
count in a Glanzmann thrombasthenia patient?
The
correct answer is: The platelet and white blood cell count
would be normal. The red count may be decreased due to bleeding
and/or concomitant iron deficiency
Pearl
Question 2: How do platelets from a Glanzmann thrombasthenia
patient appear on microscopic examination of the blood smear?
The
correct answer is: The platelets appear normal.
Pearl
Question 3: If an adult patient with no family history
of thrombasthenia or any previous bleeding disorder develops
a thrombasthenic-like condition, what should be considered
in the differential diagnosis?
The
correct answer is: Autoantibodies against GPIIb/IIIa have
been described which result in a thrombasthenic-like syndrome.
This suspicion can be confirmed by demonstrating an inhibitor
of platelet function through mixing studies using normal plasma
and normal platelets.
Pearl
Question 4: How can excessive menorrhagia be managed?
The
correct answer is: In addition to platelet transfusion
for acute bleeding, menorrhagia can be prevented with use
of oral contraception.
- George
JN, Caen JP, Nurden AT: Glanzmann's
thrombasthenia: the spectrum of clinical disease.
Blood 1990 Apr 1; PT - REVIEW, ACADEMIC(7): 1383-95.
- Malik
U, Dutcher JP, Oleksowicz L: Acquired
Glanzmann's thrombasthenia associated with Hodgkin's lymphoma:
a case report and review of the literature. Cancer
1998 May 1; PT - REVIEW LITERATURE(9): 1764-8.
- Vuckovic
SA: Glanzmann's thrombasthenia revisited.
J Emerg Med 1996 May-Jun; 14(3): 299-303.
| NOTE:
|
| Medicine
is a constantly changing science and not all therapies
are clearly established. New research changes drug and
treatment therapies daily. The authors, editors, and
publisher of this textbook have used their best efforts
to provide information that is up-to-date and accurate
and is generally accepted within medical standards at
the time of publication. However, as medical science
is constantly changing and human error is always
possible, the authors, editors, and publisher or
any other party involved with the publication of this
text do not warrant the information in this text is
accurate or complete, nor are they responsible for omissions
or errors in the text or for the results of using this
information. The reader should confirm the information
in this text from other sources prior to use. In particular,
all drug doses, indications, and contraindications should
be confirmed in the package insert.
|
Last
Modified Date : - Thursday,
14 December 2000
From
Medhelp.org: GLANZMANN'S THROMBASTHENIA - A form of congenital
platelet
functional defect that result in prolongation of the bleeding
time. Characteristics include mucosal
and post-operative bleeding that may be severe.
From Hemodyne: PCF AND GLANZMANN'S
THROMBASTHENIA
 |
Glanzmann's
thrombasthenia is an inherited, severe abnormality of
platelet functionwhich causes significant bleeding problems.
The platelets
from such patients contained reduced amount or abnormal
forms of GP IIb/IIIa. The term "thrombasthenia"
means weak platelets. Glanzmann knew that the platelets
were "weak" because clots from such patients
did not shrink or express serum. |
| Although
they contained normal numbers of platelets, these clots
behaved as if they contained no platelets. In the figure
below, PCF in samples from three such patients are compared
to a group of normals. The decrease in PCF is not subtle.
The kinetics of PCF development in Glanzmann's thrombasthenia
are similar to those seen in blood treated with GP IIb/IIIa
inhibitors. Indeed, treatment with Reopro is thought
to induce a "Glanzmann's-type deficit".
|
From
Cornel Vet : Glanzmann's thrombasthenia
 |
Glanzmann's
thrombasthenia
(also called thrombasthenic thrombopathia) is an autosomal
recessive inherited platelet disorder. This has only
been recognized in dogs and has
been found in Otterhounds and Great Pyrenees.
The defect is due to absent or dysfunctional glycoprotein
IIb/IIIa on platelets. GPIIb/IIIa is the platelet
fibrinogen receptor and is essential for platelet
aggregation (mediated by fibrinogen). |
| Affected
dogs have prolonged bleeding from minor wounds, spontaneous
epistaxis and readily form hematomas at sites of injury
or venipuncture. The dogs have a normal to mildly decreased
platelet count, normal to increased mean platelet volume
and a prolonged BMBT. Decreased platelet retention,
absent platelet aggregation to collagen, ADP, platelet
activating factor and thrombin, and decreased granule
secretion are characteristic. Shape change does occur
in response to platelet agonists. Clot retraction is
abnormal which helps differentiate this disorder
from Bassett Hound thrombopathia. The defect can be
in the gene of either glycoprotein IIb or IIIa, as both
molecules are required for proper receptor functioning.
In both Otterhounds and Great Pyrenees, the defect is
due to a genetic mutation that affects a calcium-binding
domain of the extracellular portion of glycoprotein
IIb (each breed has a different mutation). |
|
Epistaxis
in a Great Pyrenees dog with Glanzmann's thrombasthenia.
(Photograph provided courtesy of Dr. Boudreaux, Auburn
University.) |
From Adam.com: Congenital
platelet function defects
Alternative
names:
Bernard-Soulier
syndrome; Glanzmann's thrombasthenia; platelet function defects
- congenital; storage pool disease
Definition:
A disorder
of platelet function, the blood cells essential for the coagulation
of the blood, that is present at birth.
Causes,
incidence, and risk factors:
Congenital
platelet function defects are
bleeding disorders characterized by prolonged
bleeding time (the time it takes to form clotting mechanisms
in the blood) in spite of normal platelet counts. There is
usually a family history of a
bleeding disorder consisting of prolonged
bleeding or easy
bruising. Bernard-Soulier syndrome is a congenital disorder
where the
platelets lack receptors to adhere to the walls of the blood
vessels. Bleeding may be severe with this disorder. Glanzmann's
thrombasthenia is a condition which causes mucosal and postoperative
bleeding and may also be severe. Storage pool disease is a
mild bleeding disorder that causes bruising. The risk factor
is a family history of a bleeding disorder.
Dr. Richard Stevens
Glanzmann's
disease is otherwise known as Glanzmann's Thrombasthenia and
was first described in 1918. It is a hereditary condition
(autosomal recessive inheritance) and is therefore more common
where consanguineous marriages are common. Clinically, it
cannot be distinguished from other platelet disorders.
It
commonly presents in infancy or early childhood with multiple
bruises and petechial spots following minimal or unrecognisable
trauma. Nose bleeds and bleeding from the mouth is common
and may be severe. Large muscle bleeds and bleeding into joints
are uncommon but menorrhagia (heavy periods) can be severe
in girls. Serious accidental or surgical trauma can be life
threatening. The severity of the condition appears to subside
with age, probably as a result of greater discretion.
The
essential diagnostic features are a normal platelet count
and morphology and a greatly prolonged bleeding time, associated
with a complete failure of platelt aggregation with all agents
(ADP, adrenaline, thrombin and collagen) except von Willebrand
factor. Having demonstrated the aggregation defect, the diagnosis
can be confirmed by measuring the amounts of the platelet
glycoproteins Gpllb and llla in the platelet surface membrane
which are either deficient or functionally abnormal.
A
number of different variants of Glanzmann's disease have been
described of differing severity. In type 1 there is a severe
(<5%) deficiency of the platelet membrane glycoprotein
complex whereas in type ll the deficiecy is mild (5 to 20%).
Type lll has also been described where the glycoproteins are
present in normal or near normal amounts, but are functionally
defective. The genes for both glycoproteins llb and llla are
contained on chromosome 17. Many different gene abnormalities
(in different families) can give rise to the clinical condition.
Carriers
(heterozygotes) for Glanzmann's disease usually have no significant
bleeding symptoms and have normal platelet function tests.
Their platelets, however, express about half the normal number
of glycoprotein llb/llla complexes. The condition can be diagnosed
pre-natally from foetal blood samples, but carries a high
risk to an affected person from continuing haemorrhage. If
the molecular defect is known (which is not often the case),
diagnosis can be performed at 8 to 10 weeks gestation using
chronic villus sampling and the use of DNA probes. It is important
to remember that detailed counselling of the parents is necessary
before antenatal diagnosis, which is contra-indicated if the
parents wish the pregnancy to continue even if the foetus
is affected.
The
only curative treatment for Glanzmann's disease is bone marrow
transplantation. The risks of this procedure are considerable,
however, so as to confine its use to patients in which severe
bleeding cannot be adequately by more conservative measures.
Meanwhile, the management of Glanzmann's disease consists
of the avoidance of trauma and medicines such as aspirin,
which may further affect platelet function, and the treatment
of major bleeding episodes by platelet transfusion. Minor
bleeding from accessible sites (eg teeth and gums) can be
controlled by local application of thrombin and adrenaline
solutions. Severe nose bleeds may require nasal packing and
platelet transfusions. Antifibrinolytic drugs, such as Tranexamic
acid (Cyclokapron) may help control bleeding and tooth decay.
Heavy periods (menorrhagia) may be a problem and may require
hormonal therapy for control.
Excessive
platelet transfusions should be avoided because of their risk
of developing platelet antibodies. These may be antibodies
directed against the glycoprotein llb/llla complex or against
other more common platelet (HLA) determinants. HLA matched
platelets may be necessary. White cell filtration of platelets
may reduce the likelihood of developing platelet antibodies.
Dr. Richard
Stevens
Royal Manchester Childrens Hospital Pendelbury 1999
Dr.
Richard Stevens, Consultant Haematologist/Oncologist, Royal
Manchester Children's Hospital, Manchester, UK. August 2001
Glanzmann's
Thrombasthenia is a rare genetic bleeding disorder. It is
a disorder of platelet function and is caused by a deficiency
or abnormality in the membrane glycoprotein (GP) IIb-IIIa
which is responsible for the formation of a plug (haemostatic
plug) which prevents further bleeding of injured blood vessels.
In effect the platelets do not stick together adequately causing
prolonged bleeding even from minor injuries. Despite the abnormality
of platelet function, the total platelet count is normal and
specialised platelet function tests are necessary to make
the diagnosis.
Glanzmann's
Thrombasthenia may be of variable severity. Some patients
(Type 1) are severely affected whilst others are less so (Type
2). The genes for glycoprotein IIb and IIIa are on chromosome
17, but many genetic mutations have already been described.
Glanzmann's Thrombasthenia is not always the result of the
same mutation.
Normal
handling of infants can cause superficial bruises. Epistaxis
(nose bleeds) in childhood and menstrual bleeding can cause
problems.
Platelet
transfusions can be used in cases of serious bleeding. However
antibodies against platelets can develop as a result of such
transfusions. Anti-platelet drugs such as aspirin should be
avoided.
Bone marrow
transplantation is the only curative form of treatment. However
this is generally considered more hazardous than the condition
except in exceptional circumstances.
Inheritance
patterns
Autosomal recessive, carriers can now be detected.
Pre-natal
diagnosis
This is possible at 18 plus weeks through a fetal blood sample.
However where the child is affected the fetal sampling carries
a high risk of haemorrhage and may be fatal. Unaffected or
carrier fetuses will not undergo any special risk from the
testing. Genetic counselling is available.
Medical
text last updated August 2001 by Dr R F Stevens, Consultant
Haematologist/Oncologist, Royal Manchester Children's Hospital,
Manchester, UK.
GLANZMANN'S
THROMBASTHENIA CONTACT GROUP
Marilyn
Buxton Glanzmann's Thrombasthenia Contact Group
28 Duke Road Newton Hyde
SK14 4JB Tel 0161 368 0219
e-mail: glanzmannsupport@btopenworld.com
This is a Contact Group founded in 1990.
|