Disease-modifying factors in hereditary angioedema: an RNA expression-based screening

Area of Science:

• Genetics and Molecular Biology
• Immunology
• Rare Diseases

Background:

• Hereditary Angioedema (HAE) types I and II are monogenic disorders.
• Characterized by swelling due to vascular permeability deregulation.
• HAE exhibits clinical variability and low genotype/phenotype correlation, suggesting unknown factors.

Purpose of the Study:

• Investigate whole-genome RNA expression in Peripheral Blood Mononuclear Cells (PBMCs) from HAE families.
• Identify potential genetic or environmental factors contributing to HAE clinical variability.
• Explore differences in gene expression between symptomatic and asymptomatic HAE individuals.

Main Methods:

• Whole-genome RNA expression analysis of PBMCs from 40 individuals across three HAE type-I families.
• Analysis of individuals with the R472X mutation in the C1-Inhibitor gene.
• Comparison of gene expression based on mutation presence and clinical symptoms.

Main Results:

• No single, common PBMC expression pattern associated with HAE symptoms was found across all families.
• One family (DR) showed upregulated genes related to viral infection response and immune response.
• Another family (Q) displayed upregulated genes involved in transcription and protein folding; asymptomatic members had higher expression of 394 diverse genes.

Conclusions:

• Differential gene expression in PBMCs does not appear to significantly influence HAE predisposition or protection in a basal state.
• The observed viral response gene expression in one family suggests infectious diseases may modify HAE severity.
• Larger studies are needed to statistically link specific gene expression patterns to HAE development.