Hereditary hemorrhagic telangiectasia complicated by aortic sinus aneurysm caused by a pathogenic mutation in the ACVRL1 gene: a family survey / 中华皮肤科杂志

Objective:To investigate clinical and genetic characteristics of a family with hereditary hemorrhagic telangiectasia complicated by aortic sinus aneurysm, and to analyze causative genes.Methods:Clinical data and peripheral blood samples were collected from the proband and her relatives, and genomic DNA was extracted. Causative genes were screened by whole-exome sequencing, and then verified by Sanger sequencing.Results:A heterozygous mutation c.137G>A was identified at position 137 in exon 3 of the ACVRL1 gene in the proband, her daughter, grandson and granddaughter, which led to the substitution of cysteine by tyrosine at amino acid position 46 (p.C46Y) . The mutation was not found in any of the other 5 family members without clinical symptoms.Conclusion:A causative mutation c.137G>A (p.C46Y) in the ACVRL1 gene was identified in the family with hereditary hemorrhagic telangiectasia type 2 complicated by aortic sinus aneurysm, which had not been previously reported in Asian populations.

Clinical Features and Mutations in the ENG, ACVRL1, and SMAD4 genes in Korean Patients with Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder that is characterized by abnormal communication between the arteries and veins in the skin, mucosa, and various organs. HHT has been reported to show significant phenotypic variability and genetic heterogeneity with wide ethnic and geographic variations. Although mutations in the endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes have been known to cause HHT for more than 10 yr, little is known about the clinical features or genetic background of Korean patients with HHT. In addition, mutations in mothers against decapentaplegic homolog 4 (SMAD4) are also seen in patients with the combined syndrome of juvenile polyposis and HHT. This study examined five Korean patients with the typical manifestations of HHT such as frequent epistaxis and pulmonary arteriovenous malformations. Direct sequencing of the ENG and ACVRL1 genes revealed one known mutation, ENG c.277C>T, in one patient and two novel mutations, ENG c.992-1G>C and ACVRL1 c.81dupT in two patients, respectively. The remaining two patients with negative results were screened for SMAD4 mutations as well as gross deletions of ENG and ACVRL1 using multiple ligation-dependent probe amplification, but none was detected. Despite the small number of patients investigated, we firstly report Korean patients with genetically confirmed HHT, and show the genetic and allelic heterogeneity underlying HHT.