title: Characterisation and use of an intragenic polymorphic marker for detection of carriers of haemophilia B (factor IX deficiency).
abstract: DNA from 33 healthy White subjects was analysed with a 2 X 5 kilobase subgenomic DNA probe derived from the gene for coagulation factor IX, containing the exon "d" region of that gene. Intragenic Taq I restriction-fragment length polymorphism was revealed, with allelic frequencies estimated at 0 X 65 and 0 X 35 (SE = 0 X 06), also detectable by a cDNA probe. The genomic DNA probe is technically superior to the cDNA probe and has been used in three families with haemophilia B (factor IX deficiency). The polymorphic marker segregates with the deleterious mutation, allowing the identification or exclusion of carriers. The allelic frequencies of the Taq I polymorphism are virtually ideal. Therefore, such a polymorphism should be helpful both in genetic counselling of approximately 40% of affected families and in prenatal diagnosis.
mesh_terms: D000483:Alleles; D002872:Chromosome Deletion; D004247:DNA; D004262:DNA Restriction Enzymes / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific; D005164:Factor IX / Q000235:genetics*; D005260:Female; D005796:Genes; D006580:Genetic Carrier Screening / Q000379:methods*; D008040:Genetic Linkage; D005819:Genetic Markers; D002836:Hemophilia B / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008297:Male; D010375:Pedigree; D011110:Polymorphism, Genetic; D011247:Pregnancy; D011296:Prenatal Diagnosis
chemical_list: D005819:Genetic Markers; D005164:Factor IX; D004247:DNA; D004262:DNA Restriction Enzymes; D015252:Deoxyribonucleases, Type II Site-Specific; C027046:TCGA-specific type II deoxyribonucleases