Epistatic effects of immunoglobulin KM (κ marker) allotypes and ε4 allele on the risk of Alzheimer's disease.

We investigated whether immunoglobulin KM (κ marker) allotypes were associated with Alzheimer's disease (AD) individually and/or epistatically with ε4, the strongest known genetic susceptibility factor for the disease. Results showed a significant (p = 0.01) interaction between KM and ε4.

Roles of immunoglobulin GM and KM allotypes and Fcγ receptor 2 A genotypes in humoral immunity to a conserved microbial polysaccharide in pulmonary diseases.

Immunoglobulin GM (γ marker) and KM (κ marker) allotypes-encoded by immunoglobulin heavy chain G (IGHG) and immunoglobulin κ constant (IGKC) genes-have been shown to be associated with immune responsiveness to a variety of self and nonself antigens. The aim of the present investigation was to determine whether allelic variation at the GM and KM loci was associated with antibody responsiveness to poly-N-acetyl-D-glucosamine (PNAG), a broadly-conserved surface polysaccharide expressed by many microbial pathogens. In addition, we wished to determine whether Fcγ receptor 2 A (FCGR2A) genotypes, which have been shown to be risk factors for some pathogens, also influenced antibody responses to PNAG.

Immunoglobulin genes and severity of COVID-19.

There is tremendous interindividual and interracial variability in the outcome of SARS-CoV-2 infection, suggesting the involvement of host genetic factors. Here, we investigated whether IgG allotypes GM (γ marker) 3 and GM 17, genetic markers of IgG1, contributed to the severity of COVID-19. IgG1 plays a pivotal role in response against SARS-CoV-2 infection.