IgGl Protein and Corresponding IgGl Gene with the Genetic Gm Markers f, non a, and x.

An IgG1 type of protein with the genetic marker combination Gm(f), non a, and (x) has been described. The evidence from studies on isolated IgG1 Fc fragments showed that the IgG1 protein was of normal size. No Gm markers other than the three mentioned were found. Thus, there was no evidence for deletions or duplications giving rise to the unusual IgG1 protein. In contrast, the origin of the unusual genetic marker combination appears to be a rare IgG1 gene Gm^f non a, x, probably due to an intragenic recombination at the IgG1 cistron. [ABSTRACT FROM AUTHOR]