Global prevalence of hereditary hemorrhagic telangiectasia-associated variants estimated by analysis of large-scale genomic databases

Background: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder with an overwhelming hemorrhagic phenotype. It is mainly caused by variants in the ENG and ACVRL1 genes. HHT prevalence is currently estimated to be 1 in 5000 individuals, but the disease is likely underdiagnosed due to variable clinical presentation, misdiagnosis, and delayed recognition. Objectives: To estimate the global genetic prevalence of HHT-associated variants in ENG and ACVRL1. Methods: We analyzed 3 large population-scale genomic databases: gnomAD, All of Us, and Regeneron Genetics Center-Million Exome. We considered known pathogenic and likely pathogenic variants of ENG and ACVRL1 and extended the analysis to potentially pathogenic variants passing the pathogenic criteria established by the guidelines for HHT of the American College of Medical Genetics and Genomics/Association for Molecular Pathology. Results: The genetic prevalence of HHT ranged from 1.753 to 2.555 in 5000 individuals, when considering only pathogenic and likely pathogenic variants, and from 2.874 to 4.327 in 5000 individuals, when also potentially pathogenic variants were considered. Conclusion: This study assesses the prevalence of HHT-associated variants in the general population. Our unbiased approach demonstrates that the genetic prevalence of the disease is substantially higher than currently estimated.