Congenital Conotruncal Heart Defects Research Articles

BMPR2 mutations in pulmonary arterial hypertension with congenital heart disease.

The aim of the present study was to determine if patients with both pulmonary arterial hypertension (PAH), due to pulmonary vascular obstructive disease, and congenital heart defects (CHD), have mutations in the gene encoding bone morphogenetic protein receptor (BMPR)-2. The BMPR2 gene was screened in two cohorts: 40 adults and 66 children with PAH/CHD. CHDs were patent ductus arteriosus, atrial and ventricular septal defects, partial anomalous pulmonary venous return, transposition of the great arteries, atrioventicular canal, and rare lesions with systemic-to-pulmonary shunts. Six novel missense BMPR2 mutations were found in three out of four adults with complete type C atrioventricular canals and in three children. One child had an atrial septal defect and patent ductus arteriosus; one had an atrial septal defect, patent ductus arteriosus and partial anomalous pulmonary venous return; and one had an aortopulmonary window and a ventricular septal defect. Bone morphogenetic protein receptor 2 mutations were found in 6% of a mixed cohort of adults and children with pulmonary arterial hypertension/congenital heart defects. The current findings compliment recent reports in mouse models implicating members of the bone morphogenetic protein/transforming growth factor-beta pathway inducing cardiac anomalies analogous to human atrioventricular canals, septal defects and conotruncal congenital heart defects. The small number of patients studied and the ascertainment bias inherent in selecting for pulmonary arterial hypertension require further investigation.

Index of Suspicion

Index of Suspicion

Prenatal diagnosis of 22q11 microdeletion

Microdeletion of 22q11 is responsible for DiGeorge syndrome, velocardiofacial syndrome, congenital conotruncal heart defects, and related disorders. Familial transmission accounts for about 10-20 per cent of cases and most of the parents with deletions are nearly asymptomatic. This phenotypic variability makes it difficult to give appropriate genetic counselling. We report our experience on prenatal diagnosis of 22q11 deletion. We proposed prenatal detection of 22q11 microdeletion in 33 pregnancies. In two instances the parents refused prenatal diagnosis and one pregnancy ended spontaneously before the time of sampling. Fluorescent in situ hybridization (FISH) analysis on cultured amniotic cells with probes mapping in the commonly deleted region was used in the remaining 30 cases. Indications were classified into two groups. The first group included four couples with an abnormal family history of a deleted child and/or a deleted parent. No deletion was found in this group. The second one concerned pregnancies with a prenatally detected heart defect. Among these pregnancies with abnormal ultrasound findings, three deletions were found in the 26 samples tested.