Abstract
Introduction: Hereditary angioedema (HAE) is a rare disease caused by dysfunction or lack of the C1 esterase inhibitor (C1-INH) protein. The true prevalence of HAE and whether this prevalence differs across regions is uncertain. Methods: To estimate the prevalence of HAE worldwide, a systematic review and meta-analysis were performed. The pooled prevalence of HAE was calculated using a random-effects model, and heterogeneity across studies was assessed. Results: Twenty-four studies from 2000 to 2024 were included in the analysis, describing 11,245 cases of HAE. The pooled prevalence of HAE was 1.22 cases per 100,000 people (95% confidence interval [CI]: 0.91, 1.53), with lower prevalences reported in Asia and Africa compared to Europe and North America. HAE type 1 made up most of the cases, with a slight female predominance. Conclusion: HAE is a rare condition which affects 1–2 individuals per 100,000 people worldwide. A true estimate of the prevalence of HAE will inform care for the condition, especially as new treatment options become available.