COMPOUND HETEROZYGOUS COMPLEMENT C3 DEFICIENCY

Complete deficiency of the third component of the complement system is a result of defects in the two alleles of the C3 gene. In this study a family with C3 deficiency is reported; the parents expressed a disti nct abnormality of the C3 gene and their two children had compound het erozygous C3 deficiency. These are the first reported cases of compoun d heterozygous complement deficiency. Our results indicate that the ma ternal abnormality leads to synthesis of an abnormal proC3 protein whi ch is not secreted from the cells. The paternal abnormality results in ablation of synthesis of the proC3 protein.