Abstract
The Ig H chain C region is a multigene family often involved in genomic rearrangements leading to deleted and duplicated haplotypes, most probably through unequal crossing over between homologous regions within the locus. The frequency of these haplotypes in Italy is around 2.7% each. Using PFGE analysis in two unrelated Italian families we found an abnormal high m.w. band, inherited in a Mendelian fashion. To assess the extension of the haplotype we performed Southern blot analysis using several specific Ig H chain C probes. In both cases, the haplotype turned out to be triplicated, with three copies of the genes from A1 to E. In one family segregation of a duplication from EP to G4 was also observed. Analysis of polymorphic loci suggests that the two triplications are of independent origin. Serological detection of IgA2 allotypes demonstrated the functional activity of the genes at the 3' end of the triplicated locus, ruling out any major effect of these large genomic rearrangements on Ig class switching. Furthermore, the triplicated haplotype does not seem to give rise to any clinically significant immunological impairment or increase in Ig serum concentrations.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
