Mutational spectrum and geno-phenotype correlation in Chinese families with hereditary angioedema

Hereditary angioedema is a rare autosomal dominant disease, and its correlation between genotype and phenotype seems not to exist. So far, there are very few studies on Chinese population. We aimed to establish a Chinese genetic database of hereditary angioedema and investigated the potential correlation between genotype and phenotype.

All the eight exons and intron-exon boundaries of C1 inhibitor gene were detected in 48 unrelated families with HAE. The correlations between genotype and clinical parameters were evaluated by R statistical software.

Thirty-five different mutations (25 of them were novel) and 7 SNPs (3 of them were novel) were identified. Significant difference was found in the level of C1 inhibitor antigen (P = 0.01793) between different groups of mutational types. The correlation between different groups of mutational types and the level of C1 inhibitor antigen (0.5047, P = 0.00027) was significant. The different groups of mutational types showed neither difference nor correlations of clinical parameters (severity score and the level of C1 inhibitor function).

It appears that nonsense, frameshift, and mutations on Arg466 can cause lower level of C1 inhibitor antigen than missense and in-frame mutations; however, it does not affect severity of symptoms.