title: Regional localization on the human X chromosome and polymorphism of the coagulation factor IX gene (hemophilia B locus).
abstract: Hemophilia B is an X-linked disease caused by a functional deficiency in coagulation factor IX. A cDNA clone corresponding to factor IX has been used to detect homologous sequences in the human genome. All DNA fragments hybridizing to the probe, under medium- or high-stringency conditions, are X-linked, and the patterns obtained suggest that a single large (greater than or equal to 20 kilobases) gene is detected. The gene has been mapped to the q26-q27 region of the long arm of the X chromosome by hybridization to DNA from a panel of human-mouse hybrid cell lines. A search for restriction fragment length polymorphisms using seven restriction enzymes has led to the detection of a Taq I polymorphism, with allelic frequencies of about 0.71 and 0.29. This genetic marker should be useful for the detection of carriers of the hemophilia B trait and for prenatal diagnosis in informative families and, more generally, for the establishment of a linkage map of the human X chromosome.
mesh_terms: D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D005164:Factor IX / Q000235:genetics*; D005260:Female; D005796:Genes; D006801:Humans; D011110:Polymorphism, Genetic; D014960:X Chromosome
chemical_list: D005164:Factor IX; D004262:DNA Restriction Enzymes