The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

hemophilia

A hemorrhagic diathesis occurring in two main forms:

hemophilia A (classic hemophilia, factor VIII deficiency) - An X-linked disorder due to deficiency of coagulation factor VIII

hemophilia B (factor IX deficiency, Christmas disease) - Also X-linked, due to deficiency of coagulation factor IX.

Both forms are determined by a mutant gene near the telomere of the long arm of the X chromosome (Xq), but at different loci, and are characterized by subcutaneous and intramuscular hemorrhages; bleeding from the mouth, gums, lips, and tongue; hematuria, and hemarthroses.