BMPR2 haploinsufficiency as the inherited molecular mechanism for primary pulmonary hypertension

Am J Hum Genet. 2001 Jan;68(1):92-102. doi: 10.1086/316947. Epub 2000 Dec 12.

Abstract

Primary pulmonary hypertension (PPH) is a potentially lethal disorder, because the elevation of the pulmonary arterial pressure may result in right-heart failure. Histologically, the disorder is characterized by proliferation of pulmonary-artery smooth muscle and endothelial cells, by intimal hyperplasia, and by in situ thrombus formation. Heterozygous mutations within the bone morphogenetic protein type II receptor (BMPR-II) gene (BMPR2), of the transforming growth factor beta (TGF-beta) cell-signaling superfamily, have been identified in familial and sporadic cases of PPH. We report the molecular spectrum of BMPR2 mutations in 47 additional families with PPH and in three patients with sporadic PPH. Among the cohort of patients, we have identified 22 novel mutations, including 4 partial deletions, distributed throughout the BMPR2 gene. The majority (58%) of mutations are predicted to lead to a premature termination codon. We have also investigated the functional impact and genotype-phenotype relationships, to elucidate the mechanisms contributing to pathogenesis of this important vascular disease. In vitro expression analysis demonstrated loss of BMPR-II function for a number of the identified mutations. These data support the suggestion that haploinsufficiency represents the common molecular mechanism in PPH. Marked variability of the age at onset of disease was observed both within and between families. Taken together, these studies illustrate the considerable heterogeneity of BMPR2 mutations that cause PPH, and they strongly suggest that additional factors, genetic and/or environmental, may be required for the development of the clinical phenotype.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Age of Onset
  • Base Sequence
  • Bone Morphogenetic Protein Receptors, Type II
  • Cells, Cultured
  • Child
  • Child, Preschool
  • Codon, Terminator / genetics
  • DNA Mutational Analysis
  • Exons / genetics
  • Female
  • Fluorescence
  • Gene Dosage
  • Genes, Dominant / genetics*
  • Haplotypes / genetics
  • Humans
  • Hypertension, Pulmonary / epidemiology
  • Hypertension, Pulmonary / genetics*
  • Infant
  • Introns / genetics
  • Male
  • Middle Aged
  • Models, Genetic
  • Mutation / genetics*
  • Pedigree
  • Polymorphism, Genetic / genetics
  • Protein Serine-Threonine Kinases / genetics*
  • RNA Splice Sites / genetics
  • RNA, Messenger / analysis
  • RNA, Messenger / genetics
  • Sequence Deletion / genetics

Substances

  • Codon, Terminator
  • RNA Splice Sites
  • RNA, Messenger
  • Protein Serine-Threonine Kinases
  • BMPR2 protein, human
  • Bone Morphogenetic Protein Receptors, Type II