OBJECTIVETo investigate the clinical feature of a family with hereditary hemorrhagic telangiectasia (HHT), and to study the mutation of its related genes.

METHODSMedical histories of the family were analyzed to detect HHT patients according to the diagnostic criteria. ENG and ALK-1 genes of the proband and her two daughters were analyzed. DNA from the three patients' peripheral blood was extracted. The exons 2-10 and their intron-exon boundaries of ALK1 were amplified with PCR, and then the PCR products were sequenced and analyzed to identify the mutation.

RESULTSThere were 11 people in 41 family members of 4 generations were diagnosed as HHT. The proband and her two daughters suffered from multiple organ damage, the younger daughter appeared only imaging features instead of corresponding clinical symptoms. A missense mutation at the 1321 bp of cDNA (c.1321G>A) was detected in the exon 9 of ALK1, which resulted in valine 441 to methionine replacement in ALK-1 protein (p.Val441Met).

CONCLUSIONA Chinese family with HHT was studied and a missense mutation (c.1321G>A, p.Val441Met) of ALK-1 was discovered. This mutation is the genetic basis of the family with HHT and is reported for the first time in China. This research will not only help to further investigate molecular mechanism of pathogenesis of HTT, but also provide evidences and references for the following gene screening and genetic counseling on HTT family members.