Fibrinogen gamma chain locus is on chromosome 4 in man

A molecular fibrinogen variant has been detected by two-dimensional electrophoresis of human plasma samples. Fibrinogen is a complex molecule consisting of three different polypeptide chains A alpha, B beta, and gamma. The presently described variation resides in the gamma-chain, which in the variant is slightly more basic and heavier than the common form of this chain. In a family material it has been shown that the variant is genetically determined, and the segregation pattern shows autosomal codominant inheritance. The family material has been typed in approximately 30 marker systems, and linkage studies have shown close linkage between the gamma-chain locus (FGG) and MNSs. The MNSs loci are known to be located on chromosome 4 in humans and the fibrinogen gamma-chain locus is thus on this chromosome. The MNSs/FGG distance is approximately 8 centimorgans. Supplementing data suggest that FGG is distal to MNSs on the long arm of chromosome 4.