C7*N is a hypomorphic allele of the human complement c7 M/N protein polymorphism

Area of Science:

• Immunogenetics
• Complement system biology
• Protein polymorphism analysis

Background:

• The complement system is crucial for innate and adaptive immunity.
• Complement C7 (C7) protein exhibits genetic variations, known as polymorphisms or allotypes.
• Understanding C7 allotypes is important for studying its role in immune responses and disease susceptibility.

Purpose of the Study:

• To investigate the relationship between C7 protein concentrations and its known polymorphisms.
• To characterize the prevalence of C7 allotypes in a Japanese population.
• To assess potential disease associations with specific C7 allotypes.

Main Methods:

• Quantification of C7 protein levels using enzyme-linked immunosorbent assay (ELISA) with polyclonal antibodies.
• Determination of C7 allotypes using isoelectric focusing and ELISA with a monoclonal antibody.
• Comparison of C7 concentrations and functional hemolytic assay data with identified C7 allotypes.

Main Results:

• Two distinct C7 protein polymorphisms were confirmed.
• The C7*N allele, in addition to C7*3, was identified as a hypomorphic allele in the studied Japanese population.
• No significant association was found between C7*N or C7*M allotypes and diseases in hospitalized patients.

Conclusions:

• C7*N represents a hypomorphic allele, indicating reduced C7 protein function or expression.
• The characterized C7 allotypes do not appear to be major risk factors for the studied diseases in the Japanese population.
• Further research may explore the functional consequences of C7 polymorphisms in different ethnic groups or disease contexts.