Inherited structural polymorphism in human C2: evidence for genetic linkage between C2 and Bf

Area of Science:

• Immunogenetics
• Human Complement System

Background:

• The human complement system is crucial for innate and adaptive immunity.
• Complement component 2 (C2) plays a vital role in complement activation pathways.
• Understanding C2 genetic variation is important for population genetics and disease association studies.

Purpose of the Study:

• To identify and characterize structural variations in the second component of human complement (C2).
• To determine the inheritance patterns of identified C2 variants.
• To investigate potential genetic linkage between C2 and the properdin factor B (Bf) locus.

Main Methods:

• Serum samples from a diverse population were analyzed.
• Isoelectric focusing in polyacrylamide gel was used to separate C2 variants.
• Agarose gel electrophoresis with specific reagents was employed for pattern development.
• Segregation analysis was performed to assess inheritance patterns.

Main Results:

• Structural variations in C2 were found in approximately 4% of individuals across major racial groups.
• Three distinct C2 forms were identified: C2 C (common), C2 A (acidic), and C2 B (basic).
• These C2 variants demonstrated autosomal codominant inheritance.
• Suggestive evidence for close genetic linkage between C2 and Bf was observed.

Conclusions:

• Genetic polymorphism exists within the human C2 gene.
• The identified C2 variants are heritable traits following codominant inheritance.
• The findings support a potential genetic linkage between C2 and Bf, relevant for immunogenetic research.