The identification of a DNA polymorphism of the α fibrinogen gene, and the regional assignment of the human fibrinogen genes to 4q26-qter

We have identified a common restriction fragment length polymorphism of the α fibrinogen gene with the enzyme TaqI. This polymorphism is probably due to a single base change that creates or destroys a TaqI recognition site about 1000 basepairs from the 3′ end of the α fibrinogen gene. The frequency of the rare allele in 83 unrelated healthy individuals is 0.33. We have used in situ hybridisation of the α fibrinogen cDNA to localise the gene on chromosome 4q29–31. We have confirmed this regional localisation by restriction fragment detection in a human x Chinese hamster somatic cell hybrid which contains a translocated human chromosome 4 with a breakpoint at 4q26. The α, β, and γ fibrinogen genes are all present on human chromosome 4q26-qter.