Biomaterial Database

The molecular pathology of haemophilia B. Fourth Wellcome Trust lecture. 1987

G G Brownlee

Haemophilia is a rare inherited disease of blood clotting known since biblical times. The rarer form (haemophilia B) occurs in about 1 in 30,000 males and there are about 900 patients in the U.K. at present. Biochemically, patients either lack or have a defective protein (called factor IX) which is needed for the clotting of blood in response to injury. Only males get the disease. However, females can carry the trait in a latent form and transmit the disease to their offspring. Untreated, the disease leads to internal bleeding into muscles and joints and is life-threatening. In the U.K. and in countries with effective health care programmes, patients are treated by periodic injection of factor IX concentrate, a drug isolated from the pooled plasma derived from many blood donors. This drug replaces their own absent or defective factor IX and allow them to enjoy a relatively normal lifestyle. I have reviewed recent studies on the molecular genetics of haemophilia B which started with the isolation of the gene coding the factor IX protein from normal individuals in 1984. Following this, it has been possible firstly to produce factor IX artificially in the laboratory from cloned copies of the messenger RNA of the factor IX gene. Secondly, it has been possible to improve the diagnosis of 'carriers'. Carrier females often wish to know whether they are carriers or not before they have children. If they are positively identified as carriers, the risk and implications of having a haemophiliac son can be discussed and therapeutic abortion considered.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D011110	Polymorphism, Genetic	The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.	Gene Polymorphism,Genetic Polymorphism,Polymorphism (Genetics),Genetic Polymorphisms,Gene Polymorphisms,Polymorphism, Gene,Polymorphisms (Genetics),Polymorphisms, Gene,Polymorphisms, Genetic
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D005164	Factor IX	Storage-stable blood coagulation factor acting in the intrinsic pathway of blood coagulation. Its activated form, IXa, forms a complex with factor VIII and calcium on platelet factor 3 to activate factor X to Xa. Deficiency of factor IX results in HEMOPHILIA B (Christmas Disease).	Autoprothrombin II,Christmas Factor,Coagulation Factor IX,Plasma Thromboplastin Component,Blood Coagulation Factor IX,Factor 9,Factor IX Complex,Factor IX Fraction,Factor Nine,Factor IX, Coagulation
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
D006467	Hemophilia A	The classic hemophilia resulting from a deficiency of factor VIII. It is an inherited disorder of blood coagulation characterized by a permanent tendency to hemorrhage.	Factor VIII Deficiency,Hemophilia,Autosomal Hemophilia A,Classic Hemophilia,Deficiency, Factor VIII,Factor 8 Deficiency, Congenital,Factor VIII Deficiency, Congenital,Haemophilia,Hemophilia A, Congenital,Hemophilia, Classic,As, Autosomal Hemophilia,Autosomal Hemophilia As,Classic Hemophilias,Congenital Hemophilia A,Congenital Hemophilia As,Hemophilia A, Autosomal,Hemophilia As,Hemophilia As, Autosomal,Hemophilia As, Congenital,Hemophilias, Classic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA