Related Experiment Videos
Inherited deficiency of the sixth component of complement: a silent or null gene
Insights
Inherited deficiency of the sixth component of complement (C6) was studied in four families. Researchers identified a silent or null C6 gene, suggesting allelic inheritance for C6 variants and low serum levels.
Area of Science:
- Immunogenetics
- Complement system biology
- Human genetics
Background:
- The sixth component of complement (C6) is crucial for the membrane attack complex formation.
- Inherited C6 deficiency is a rare genetic disorder.
- Electrophoretic variants of C6 can be identified in human serum.
Purpose of the Study:
- To investigate the genetic basis of inherited C6 deficiency in four families.
- To identify the inheritance patterns of C6 electrophoretic variants and low serum levels.
- To determine the allelic relationship between C6 variants and C6 deficiency.
Main Methods:
- Family-based genetic study design.
- Electrophoretic analysis of C6 in serum samples from family members.
- Segregation analysis of C6 variants and deficiency phenotypes within families.
Main Results:
- Four families with inherited C6 deficiency were analyzed.
- Electrophoretic variants of C6 were identified in family members.
- Seven individuals exhibited C6 levels inconsistent with the parental variant, suggesting a silent or null allele.
- The genes for C6 electrophoretic variants and low serum levels were found to be allelic.
Conclusions:
- Inherited C6 deficiency can result from the heterozygous state of a normal C6 variant allele and a silent or null C6 allele.
- The genetic determinants for C6 electrophoretic variants and low serum C6 levels are allelic.
- This study elucidates the genetic mechanisms underlying C6 deficiency and variant expression.
Abstract:
Four families have been studied, some members of which have inherited deficiency of the sixth component of complement. The genetically determined electrophoretic variants of C6 were evaluated in all family members. Seven individuals were found who did not have the variant found in the serum of the parent from whom they inherited the deficiency. It is inferred that the isolated low levels of C6 in these individuals results from the heterozygous state of a normal C6 variant gene and a silent or null C6 gene; the genes determining electrophoretic variants and the low serum levels of C6 are allelic.