Approximate linkage equilibrium between two polymorphic sites within the gene for human complement component 3.

Haplotypes have been determined for alleles at two separate polymorphic sites within the human structural gene for complement component 3, identified as a protein polymorphism and as a restriction fragment length polymorphism by hybridization using a cloned gene probe. No evidence was found for appreciable disequilibrium between alleles at these sites, despite their very close linkage.