Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Molecular Genetics of HemophiliaSlide 8Hemophilia ASlide 10Slide 11Slide 12Hemophilia A: GeneticsX-Linked Recessive InheritanceSlide 15Slide 16Factor VIIIMolecular Defects in Hemophilia ASlide 19FVIII Gene Inversion (Intron 22)Genetic Diagnosis for Hemophilia ASlide 22Slide 23VWF/Factor VIII InteractionType 2N VWD (VWD Normandy)Combined Deficiency of Factors V and VIIISlide 27Slide 28Hemophilia BFactor IXHemophilia B: GeneticsMolecular Defects in Hemophilia BSlide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Molecular Genetics of Hemophilia SummaryREAD:Gelehrter et al. pages 137-143SEE: Course web site, lecture notesBleeding disorders have been recognized since ancient times…• The Talmud (2nd century AD) states that male babies do not have to be circumcised if two brothers have died from the procedure• In 12th century Albucasis, an Arab physician, wrote about a family in which males died of excessive bleeding from minor injuries• In 1803, Dr. John Otto, Philadelphia, wrote about an inherited hemorrhagic disposition affecting males• In 1828 at the University of Zurich, “hemophilia" was first used to describe a bleeding disorderplatelet plugfibrin clotvasoconstrictionvascular injuryincompleteplatelet plugincomplete or delayedfibrin clotvasoconstrictionvascular injuryNORMALBLEEDING DISORDERA “Royal Disease” Queen Victoria (1837 to 1901) passed hemophilia on to German, Russian and Spanish royal families. Her son, Leopold, had frequent hemorrhages (British Medical Journal,1868) and died of a brain hemorrhage at 31. His grandson also died of a brain hemorrhage in 1928.extrinsic pathwayintrinsic pathwayTypes of Bleeding Disorders von Willebrand disease Factor I deficiencyFactor II deficiencyFactor V deficiency Factor VII deficiencyFactor VIII deficiency (Hemophilia A) Factor IX deficiency (Hemophilia B)Factor X deficiency Factor XI deficiency Factor XII deficiencyFactor XIII deficiencyMolecular Genetics of HemophiliaMolecular Genetics of Hemophilia•Hemophilia A Hemophilia A –Factor VIII deficiencyFactor VIII deficiency•Other Genetic Disorders with low Factor VIIIOther Genetic Disorders with low Factor VIII–Von Willebrand Disease (Type 2N)Von Willebrand Disease (Type 2N)–Combined Deficiency of Factor V and Factor VIIICombined Deficiency of Factor V and Factor VIII•Hemophilia BHemophilia B–Factor IX deficiencyFactor IX deficiencyextrinsic pathwayintrinsic pathwayHemophilia AHemophilia A•Incidence 1:5,000 - 1:10,000 malesIncidence 1:5,000 - 1:10,000 males– about as rare as the birth of tripletsabout as rare as the birth of triplets–~ 1 in 5,000 live male births are affected. ~ 1 in 5,000 live male births are affected. –~ 15,000 to 20,000 people with hemophilia in the US~ 15,000 to 20,000 people with hemophilia in the US•Hemarthroses, post-traumatic and post-surgical bleedingHemarthroses, post-traumatic and post-surgical bleeding•Severity related to factor VIII levelSeverity related to factor VIII level–<1% = severe<1% = severe–1-5% = moderate1-5% = moderate–5-15% = mild5-15% = mild•Inhibitors develop in ~10-20% of severe patientsInhibitors develop in ~10-20% of severe patientsSymptoms of hemophilia include...Primary: Bruising and Bleeding Minor bleeds:•early joint and muscle bleeds•bleeding in the mouth and gums•epistaxis (nosebleed), •hematuria (blood in the urine)Major bleeds •central nervous system•severe injury•neck/throat, eye, gastrointestinal, hip, iliopsoas, late joint and muscle, testicles, and retroperitoneum bleedsSecondary:• Chronic joint deformities from recurrent bleeding • Antibodies to transfused factor VIII (inhibitors develop only in 20-30% of severe patients, not in mild-moderate) • AIDS - Over 60 %of persons with hemophilia treated with plasma concentrates in the early 1980s became HIV+Mild hemophilia patients (factor levels >5% and <50%) - usually bleed only after injury or surgery- some never have a major bleed, others have several episodes depending on functional factor levels- carriers of hemophilia may fall in the mild rangeModerate hemophilia patients (factor levels 2% to 5%) - bleed about one a month, usually after trauma, surgery, or exertion. - once a bleeding history is established in an area, may have spontaneous bleeding episodes into those areasSevere hemophilia patients (factor levels <1%) - bleed very easily, sometimes spontaneously with no warning and for no apparent reason, usually targeting the joints but potentially in any areaHemophilia A: GeneticsHemophilia A: Genetics•X-linked inheritanceX-linked inheritance–~1/3 patients represent new mutations (Haldane hypothesis)~1/3 patients represent new mutations (Haldane hypothesis)•Germinal mosaicismGerminal mosaicism•Low FVIII in female consider:Low FVIII in female consider:–skewed X-inactivationskewed X-inactivation–chromosomal abnormality (normal X inactivated)chromosomal abnormality (normal X inactivated)–VWD (particularly type 2N)VWD (particularly type 2N)X-Linked Recessive InheritanceX-Linked Recessive InheritanceCarrier femaleCarrier femaleAffected maleAffected maleNormal maleNormal male•Affected males (XY):Affected males (XY):–sons unaffected (no male to male transmission)sons unaffected (no male to male transmission)–daughters obligate carriersdaughters obligate carriers•Carrier female (XX): Carrier female (XX): –½ sons affected; ½ daughters carriers½ sons affected; ½ daughters carriers•Affected females: very rare.Affected females: very rare.New mutation in New mutation in germ cellgerm cellNew mutation in New mutation in maternal or maternal or paternal germ cellpaternal germ cellIs this woman a hemophilia carrier of hemophilia? • A biological daughter of a man with hemophilia• A biological mother of one son with hemophilia • A biological mother of more than one son with hemophilia • A biological mother of one hemophilic son and has at least one other blood relative with hemophilia• A sister of a male with hemophilia46, XX46, XYFactor VIII allele - normalMutant VIII allele - normalGermline/Gonadal MosaicismovarytestesFactor VIIIFactor VIII•Factor VIII geneFactor VIII gene–X-chromosome (Xq28), 186 kb, 26 exonsX-chromosome (Xq28), 186 kb, 26 exons•300 kDa protein:300 kDa protein:•Biosynthesis: ?liver, ?lymphocytes, ?subset of ECsBiosynthesis: ?liver, ?lymphocytes,