Mutation in the gene for bone morphogenetic protein receptor II as a cause of primary pulmonary hypertension in a large kindred.
BACKGROUND
Most patients with primary pulmonary hypertension are thought to have sporadic, not inherited, disease. Because clinical disease develops in only 10 to 20 percent of persons carrying the gene for familial primary pulmonary hypertension, we hypothesized that many patients with apparently sporadic primary pulmonary hypertension may actually have familial primary pulmonary hypertension.


METHODS
In a study conducted over 20 years, we developed a registry of 67 families affected by familial primary pulmonary hypertension. Through patient referrals, extensive family histories, and correlation of family pedigrees, we discovered shared ancestry among five subfamilies. We established the diagnosis of primary pulmonary hypertension by direct evaluation of patients and review of autopsy material and medical records. We assessed some family members for mutations in the gene encoding bone morphogenetic protein receptor II (BMPR2), which has recently been found to cause familial primary pulmonary hypertension.


RESULTS
We linked five separately identified subfamilies that included 394 known members spanning seven generations, which were traced back to a founding couple in the mid-1800s. Familial primary pulmonary hypertension has been diagnosed in 18 family members, 12 of whom were first thought to have sporadic disease. The conditions of 7 of the 18 were initially misdiagnosed as other cardiopulmonary diseases. Six members affected with familial primary pulmonary hypertension and 6 of 10 at risk for carriage have been undergone genotype analysis, and they have the same mutation in BMPR2, a transversion of thymine to guanine at position 354 in exon 3.


CONCLUSIONS
Many cases of apparently sporadic primary pulmonary hypertension may be familial. Failure to detect familial primary pulmonary hypertension results from incomplete expression within families, skipped generations, and incomplete family pedigrees. The recent discovery of mutations in BMPR2 should make it possible to identify those with susceptibility to disease.
Newman
J H
JH
Center for Lung Research, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA. john.newman@med.va.gov
Wheeler
L
L
Lane
K B
KB
Loyd
E
E
Gaddipati
R
R
Phillips
J A
JA
Loyd
J E
JE
D000328:Adult; D052006:Bone Morphogenetic Protein Receptors, Type II; D019485:Bone Morphogenetic Proteins / Q000502:physiology; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2; D003951:Diagnostic Errors; D005260:Female; D006579:Heterozygote; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D020125:Mutation, Missense; D010375:Pedigree; D017354:Point Mutation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*
D019485:Bone Morphogenetic Proteins; D017346:Protein Serine-Threonine Kinases; C498218:BMPR2 protein, human; D052006:Bone Morphogenetic Protein Receptors, Type II