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Background: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder, affecting 1:5000 individuals worldwide. All the genes associated to the disease (ENG, ACVRL1, SMAD4, GDF2) belong to the TGF-β/BMPs signaling pathway. We found 19 HHT unrelated families, coming from a Northern Italy region and sharing the ACVRL1 in-frame deletion c.289_294del (p.H97_N98)., Methods: To test the hypothesis of a founder effect, we analyzed 88 subjects from 19 families (66 variant carriers, showing clinical signs of HHT, and 22 non-carriers, unaffected) using eight microsatellite markers within 3.7 Mb around the ACVRL1 locus. After the haplotype reconstruction, age estimation of the variant was carried out., Results: We observed a common disease haplotype in 16/19 families, while three families showed evidence of recombination around the ACVRL1 locus. The subsequent age estimation analyses suggested that the mutation occurred about 8 generations ago, corresponding to about 200 years ago. We also present novel in silico and modeling data supporting the variant pathogenicity: the deletion alters the protein stability and removes the unique extracellular glycosylation site., Conclusion: We have demonstrated, for the first time, a "founder effect" for a HHT pathogenic variant in Italy., (© 2022 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Background: Hereditary hemorrhagic telangiectasia (HHT) is a vascular dysplasia disorder characterized by epistaxis, mucocutaneous telangiectasias and arteriovenous malformations in internal organs. Recurrent epistaxis is the primary complaint in 90%-96% of HHT patients and the other symptoms come with age. The aim of this study was to analyze HHT-associated gene variant spectrum in Chinese HHT patients and to assess whether genetic testing could contribute to the early diagnosis., Methodology/principal: Thirty one HHT families including 62 individuals were recruited. Variants in the coding regions of four genes involved in HHT were amplified and analyzed using Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA)., Results: Twenty unique variants, including 8 novel variants were found in 24 of the 31 (77.4%) kindred. Diagnosis is confirmed for 7 possible individuals from 6 kindred. Thirteen ACVRL1 variants were detected from 17 isolated HHT families. Variants in ACVRL1 from 8/17 (47.1%) families were located in exon8. Seven ENG variants were found in 7 unrelated families throughout the coding region., Conclusion: We conclude that ACVRL1 gene variant is 2.4 times more prevalent than that in ENG in Chinese individuals with HHT, and exon8 of the ACVRL1 gene may be a hotspot region. Genetic testing could contribute to early diagnosis for HHT., (© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Background: We aimed to provide a set of previously reported PAH-associated missense and nonsense variants, and evaluate the pathogenicity of those variants., Methods: The Human Gene Mutation Database, PubMed, and Google Scholar were searched for previously reported PAH-associated genes and variants. Thereafter, both exome sequencing project and exome aggregation consortium as background population searched for previously reported PAH-associated missense and nonsense variants. The pathogenicity of previously reported PAH-associated missense variants evaluated by using four in silico prediction tools., Results: In total, 14 PAH-associated genes and 180 missense and nonsense variants were gathered. The BMPR2, the most frequent reported gene, encompasses 135 of 180 missense and nonsense variants. The exome sequencing project comprised 9, and the exome aggregation consortium counted 25 of 180 PAH-associated missense and nonsense variants. The TOPBP1 and ENG genes are unlikely to be the monogenic cause of PAH pathogenesis based on allele frequency in background population and prediction analysis., Conclusion: This is the first evaluation of previously reported PAH-associated missense and nonsense variants. The BMPR2 identified as the major gene out of 14 PAH-associated genes. Based on findings, the ENG and TOPBP1 gene are not likely to be the monogenic cause of PAH., (© 2018 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Patients who harbor brain arteriovenous malformations are at risk for intracranial hemorrhage. These malformations are often seen in inherited vascular diseases such as hereditary hemorrhagic telangiectasia. However, malformations within the brain also sporadically occur without a hereditary-coding component. Here, we review recent insights into the pathophysiology of arteriovenous malformations, in particular, certain signaling pathways that might underlie endothelial cell pathology. To better interpret the origins, determinants and consequences of brain arteriovenous malformations, we present a clinical case to illustrate the phenotypic landscape of the disease. We also propose that brain arteriovenous malformations might share certain signaling dimensions with those of anorectal hemorrhoids. This working hypothesis provides casual anchors from which to understand vascular diseases characterized by arteriovenous lesions with a hemorrhagic- or bleeding-risk component. Anat Rec, 2017. © The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists. Anat Rec, 300:1973-1980, 2017. © 2017 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists., (© 2017 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.)