Published ahead of print on May 25, 2006, doi:10.1164/rccm.200602-165OC
© 2006 American Thoracic Society doi: 10.1164/rccm.200602-165OC
High Frequency of BMPR2 Exonic Deletions/Duplications in Familial Pulmonary Arterial HypertensionDivisions of Medical Genetics and Pulmonary Biology, Vanderbilt University Medical Center, Nashville, Tennessee; and Division of Human Genetics, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio Correspondence and requests for reprints should be addressed to William C. Nichols, Ph.D., Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, 1469 TCHRF, Cincinnati, OH 45229. E-mail: bill.nichols{at}cchmc.org Rationale: Previous studies have shown that approximately 55% of patients with familial pulmonary arterial hypertension (FPAH) have BMPR2 coding sequence mutations. However, direct sequencing does not detect other types of heterozygous mutations, such as exonic deletions/duplications. Objective: To estimate the frequency of BMPR2 exonic deletions/duplications in FPAH. Methods: BMPR2 mRNA from lymphoblastoid cell lines of 30 families with PAH and 14 patients with idiopathic PAH (IPAH) was subjected to reverse transcriptase–polymerase chain reaction (RT-PCR) and sequencing. Sequencing of genomic DNA was used to identify point mutations in splice donor/acceptor sites. Multiplex ligation-dependent probe amplification (MLPA) was used to detect exonic deletions/duplications with verification by real-time PCR. Measurements and Main Results: Eleven (37%) patients with FPAH had abnormally sized RT-PCR products. Four of the 11 patients were found to have splice-site mutations resulting in aberrant splicing, and exonic deletions/duplications were detected in the remaining seven patients. MLPA identified three deletions/duplications that were not detectable by RT-PCR. Coding sequence point mutations were identified in 11 of 30 (37%) patients. Mutations were identified in 21 of 30 (70%) patients with FPAH, with 10 of 21 mutations (48%) being exonic deletions/duplications. Two of 14 (14%) patients with IPAH exhibited BMPR2 point mutations, whereas none showed exonic deletions/duplications. Conclusions: Our study indicates that BMPR2 exonic deletions/duplications in patients with FPAH account for a significant proportion of mutations (48%) that until now have not been screened for. Because the complementary approach used in this study is rapid and cost effective, screening for BMPR2 deletions/duplications by MLPA and real-time PCR should accompany direct sequencing in all PAH testing.
Key Words: dosage • genetics • multiplex ligation-dependent probe amplification This article has been cited by other articles:
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
