Showing papers on "Alveolar capillary dysplasia published in 2007"

Mutations in STRA6 cause a broad spectrum of malformations including anophthalmia, congenital heart defects, diaphragmatic hernia, alveolar capillary dysplasia, lung hypoplasia, and mental retardation

Abstract: We observed two unrelated consanguineous families with malformation syndromes sharing anophthalmia and distinct eyebrows as common signs, but differing for alveolar capillary dysplasia or complex congenital heart defect in one and diaphragmatic hernia in the other family. Homozygosity mapping revealed linkage to a common locus on chromosome 15, and pathogenic homozygous mutations were identified in STRA6, a member of a large group of "stimulated by retinoic acid" genes encoding novel transmembrane proteins, transcription factors, and secreted signaling molecules or proteins of largely unknown function. Subsequently, homozygous STRA6 mutations were also demonstrated in 3 of 13 patients chosen on the basis of significant phenotypic overlap to the original cases. While a homozygous deletion generating a premature stop codon (p.G50AfsX22) led to absence of the immunoreactive protein in patient's fibroblast culture, structural analysis of three missense mutations (P90L, P293L, and T321P) suggested significant effects on the geometry of the loops connecting the transmembrane helices of STRA6. Two further variations in the C-terminus (T644M and R655C) alter specific functional sites, an SH2-binding motif and a phosphorylation site, respectively. STRA6 mutations thus define a pleiotropic malformation syndrome representing the first human phenotype associated with mutations in a gene from the "STRA" group.

FGF9 and SHH regulate mesenchymal Vegfa expression and development of the pulmonary capillary network.

Abstract: The juxtaposition of a dense capillary network to lung epithelial cells is essential for air-blood gas exchange. Defective lung vascular development can result in bronchopulmonary dysplasia and alveolar capillary dysplasia. Although vascular endothelial growth factor A (Vegfa) is required for formation of the lung capillary network, little is known regarding the factors that regulate the density and location of the distal capillary plexus and the expression pattern of Vegfa. Here, we show that fibroblast growth factor 9 (FGF9) and sonic hedgehog (SHH) signaling to lung mesenchyme, but not to endothelial cells, are each necessary and together sufficient for distal capillary development. Furthermore, both gain- and loss-of-function of FGF9 regulates Vegfa expression in lung mesenchyme, and VEGF signaling is required for FGF9-mediated blood vessel formation. FGF9, however, can only partially rescue the reduction in capillary density found in the absence of SHH signaling, and SHH is unable to rescue the vascular phenotype found in Fgf9(-/-) lungs. Thus, both signaling systems regulate distinct aspects of vascular development in distal lung mesenchyme. These data suggest a molecular mechanism through which FGF9 and SHH signaling coordinately control the growth and patterning of the lung capillary plexus, and regulate the temporal and spatial expression of Vegfa.

Severe neonatal manifestations of Costello syndrome

Abstract: Background: Costello syndrome (CS) is due to mutations in HRAS, with the commonest mutation being c.34G>A (p.G12S), found in most patients in all the published series1,3-7. A small number of less common mutations have been reported. Population studied: HRAS mutation analysis has been undertaken in 74 predominantly British patients with a possible diagnosis of Costello syndrome. A HRAS mutation was found in 27 patients, 15 of whom have been previously reported3. Phenotype analysis: Four cases had an unusually severe phenotype, associated in three cases with two unusual mutations, c.35G>A, p.G12D in two cases and c.34G>T, p.G12C in the other. Hypoglycaemia, renal abnormalities, severe early cardiomyopathy, congenital lung and airway abnormalities, pleural and pericardial effusion, chylous ascites and pulmonary lymphangectasia are confirmed as part of the clinical spectrum seen in CS. A lung pathology resembling alveolar capillary dysplasia is reported in one case. Conclusion: These cases illustrate that the diagnosis of Costello syndrome may be difficult in the newborn period, and should be considered in the differential diagnosis of the sick newborn infant with multi-system disease. Study of more cases will be required to establish if there is a definite association between severe disease and less common mutations.

A rare case of aortic coarctation and ventricular septal defect combined with alveolar capillary dysplasia.

Abstract: We report a rare case of alveolar capillary dysplasia (ACD) associated with severe aortic coarctation, hypoplastic aortic arch, and mild hypoplasia of the left ventricle. After successful coarctation repair, pulmonary hypertension persisted, and despite only minor anomalies on the x-ray, chest computed tomography (CT) revealed the presence of primary lung disease. Review of the literature suggests that ACD may be associated with left heart obstructions. Chest CT is applicable to diagnose ACD precociously.

Alveolar capillary dysplasia presenting as pneumothorax: a case report and review of literature.

Abstract: Alveolar capillary dysplasia, although rare, is a universally fatal form of persistent pulmonary hypertension of the newborn. We report a case of a newborn male baby who developed respiratory distress and pneumothorax 11 h after an uncomplicated delivery. He deteriorated despite full ventilatory support and extracorporeal membrane oxygenation (ECMO). Open lung biopsy provided a diagnosis of alveolar capillary dysplasia and decision was made to withdraw treatment.

La dysplasie alvéolo-capillaire : une cause exceptionnelle d’hypertension artérielle pulmonaire persistante du nouveau né. A propos d’un cas

Abstract: Alveolar capillary dysplasia is a rare cause of persistent pulmonary hypertension of the newborn. The diagnosis of this condition is made by histological study of a pulmonary biopsy. Familial forms and associated genitor-urinary and gastrointestinal malformations have been reported. Despite optimal management, the prognosis remains poor. The authors report the case of a neonate who developed cyanosis and cardiogenic shock on the 10th day of life. There was no associated neonatal pathology. Echocardiography showed supra-systemic pulmonary hypertension with normal cardiac structure. Pulmonary vasodilator therapies (inhaled NO, prostacyclin, sildenafil, bosentan) were ineffective and the child died on the 25th day of life. Autopsy revealed alveolar capillary dysplasia.