ABSTRACT
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.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Young Adult , Activin Receptors, Type II/genetics , Alleles , Angiography , Antigens, CD/genetics , Asian People/genetics , Base Sequence , Genetic Predisposition to Disease , Korea , Mutation , Pedigree , Receptors, Cell Surface/genetics , Smad4 Protein/genetics , Telangiectasia, Hereditary Hemorrhagic/diagnosis , Tomography, X-Ray ComputedABSTRACT
Ehlers-Danlos syndrome (EDS) is a hereditary disorder of the connective tissue. EDS type IV (EDS IV), the vascular type of the disease, is characterized by easy bruising, thin skin with visible veins, and spontaneous rupture of the large arteries, uterus, or bowel. EDS IV is caused by mutations in the gene for type III procollagen (COL3A1). However, recent studies suggest that the causative mutation of EDS IV is not homogeneous. We report our experience with three patients presenting with clinical features of type IV EDS. A 48-yr-old woman presented with acute aortic dissection (patient 1) and 36-yr-old and 21-yr-old women presented with carotidcavernous fistula (patients 2 and 3, respectively). All three patients bruised easily. Two patients (patients 1 and 3) had thin transparent skin with visible veins. Genetic analysis of COL3A1 revealed a Gly732Val (c.2195G>T) mutation in patient 1 and a duplication of 15 base pairs (c.3221_3235dup) which resulted in an interposition of five amino acids (p.Gly1074_Pro1078dup) in patient 2. However, no mutations were observed in COL3A1 or transforming growth factor beta receptors 1 and 2 in patients 3, which might be either due to a deletion of single or multiple exons in the COL3A1 gene or due to a genetic heterogeneity. This is the first report of genetically confirmed cases of EDS IV in Korea.