bio chem presentation on hemophilia
TRANSCRIPT
HaemophiliaBy:
Kacy Amora
Anuradha Boodoo-Balliram
Pella Charles
Natherly Ferguson
Candace Lewis
What is Haemophilia?
•Haemophilia is a bleeding disorder that
slows the blood clotting process. People with
this condition experience prolonged bleeding.
•The major types of this condition are
haemophilia A (factor VIII deficiency) and
haemophilia B (factor IX deficiency
History of Haemophilia
•First recognized by the Jews
•It became known as the royal
disease
•The word ‘haemophilia’ was first
used in 1828
•In 1952 haemophilia B was named
after Stephen Christmas.
HOW IS HAEMOPHILIA INHERITED
CLASSIFICATION OF HAEMOPHILIA
CLASSIFICATION LEVEL OF FACTOR VII OR IX IN THE BLOOD
Severe Less than 1% of normal
Moderate 1% to 5% of normal
Mild 5% to 30% of normal
DEMOGRAPHICS•Haemophilia occur much more commonly in males.
•Haemophilia A is the most common type of the condition;
1 in 4,000 to 1 in 5,000 males worldwide are born with
this disorder.
•Haemophilia B occurs in approximately 1 in 20,000
newborn males worldwide.
•By race/ethnicity, the prevalence is 13.2 cases in 100,000
among white males, 11.0 among African-American males,
and 11.5 among Hispanic males.
•Haemophilia C occurs primarily among individuals of
Jewish descent
BIOCHEMICAL BASIS OF HAEMOPHILIA
Homeostasis- Cessation of bleeding. Coagulation of bleeding.
Two types of hemostasis:
• Primary hemostasis: A platelet plug is formed
• Secondary hemostasis: Blood clot formation
Homeostasis
Secondary Homeostasis –Coagulation Cascade
•Haemophilia A
•Classic haemophilia
• Factor VIII deficiency
•Haemophilia B
•Christmas disease
• Factor IX deficiency
Gene Structure and Expression
•Hemophilia may be caused by a
defect in one of the genes that
determine how the body makes
blood clotting factor VIII or IX.
•The genes are located on the X
chromosome.
X chromosome
• Factor VIII gene- long arm in band q28
• Factor IX gene - q26.3-27.1
Biosynthesis and Biochemistry Factor VIII
•Factor VIII or antihemophilic factor
•A nonenzymatic protein
•2351 amino acids
•Circulates in plasma in complex with von
Willibrand Factor(vWF)
•Biosynthesis occurs in the liver and spleen
primarily.
•Function -participate in blood coagulation.
•It is a cofactor for factor IXa which converts
factor X to the activated form (Xa).
Biosynthesis and Biochemistry Factor IX•Factor IX (Christmas factor, or hemophilia B factor)
•Produced as a zymogen and circulates in plasma.
•415 amino acids.
•Is a member of the vitamin K–dependent protein family
•Is cleaved by factor XIa or factor VIIa to produce a two-
chain form where the chains are linked by a disulfide bridge.
•When activated into factor IXa, in the presence of Ca2+,
membrane phospholipids, and a Factor VIII cofactor, it
hydrolyses one arginine-isoleucine bond in factor X to form
factor Xa.
•Function-in blood coagulation it activates factor X to factor
Xa.
SIGNS and SYMPTOMS of HAEMOPHILIA
1. Excessive Bleeding: bleeding can occur
externally or internally
•External
• Bleeding in the mouth from a cut or bite
or from cutting or losing a tooth
• Nosebleeds for no obvious reason
• Heavy bleeding from a minor cut
• Bleeding from a cut that resumes after
stopping for a short time
Internal Bleeding
•Blood in the urine (from bleeding in
the kidneys or bladder)
•Blood in the stool (from bleeding in the
intestines or stomach)
• Large bruises (from bleeding into the
large muscles of the body)
Bleeding in the joints:
•Bleeding in the knees, elbows, or other
joints is another common form of internal
bleeding
•The bleeding causes tightness in the joint
with no real pain or any visible signs of
bleeding.
•The joint then becomes swollen, hot to
touch, and painful to bend. Swelling
continues as bleeding continues.
•Movement in the joint is temporarily lost
Bleeding in the brain:
• Long-lasting, painful headaches or neck
pain or stiffness
• Repeated vomiting
• Sleepiness or changes in behaviour
• Sudden weakness or clumsiness of the
arms or legs or problems walking
• Double vision
• Convulsions or seizures
DIAGNOSIS
•By family history
•Haemophilia is diagnosed by
taking sample and measuring the
level of factor activity in the blood.
TREATMENT OPTIONS
•Treatment with Replacement
Therapy
•Desmopressin
•Antifibrinolytic Medicines
•Treatment of a Specific Bleeding
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