Showing papers on "Alveolar capillary dysplasia published in 2017"

The Role of Serotonin Transporter in Human Lung Development and in Neonatal Lung Disorders.

Abstract: Introduction. Failure of the vascular pulmonary remodeling at birth often manifests as pulmonary hypertension (PHT) and is associated with a variety of neonatal lung disorders including a uniformly fatal developmental disorder known as alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV). Serum serotonin regulation has been linked to pulmonary vascular function and disease, and serotonin transporter (SERT) is thought to be one of the key regulators in these processes. We sought to find evidence of a role that SERT plays in the neonatal respiratory adaptation process and in the pathomechanism of ACD/MPV. Methods. We used histology and immunohistochemistry to determine the timetable of SERT protein expression in normal human fetal and postnatal lungs and in cases of newborn and childhood PHT of varied etiology. In addition, we tested for a SERT gene promoter defect in ACD/MPV patients. Results. We found that SERT protein expression begins at 30 weeks of gestation, increases to term, and stays high postnatally. ACD/MPV patients had diminished SERT expression without SERT promoter alteration. Conclusion. We concluded that SERT/serotonin pathway is crucial in the process of pulmonary vascular remodeling/adaptation at birth and plays a key role in the pathobiology of ACD/MPV.

Maternal mutations of FOXF1 cause alveolar capillary dysplasia despite not being imprinted.

Abstract: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a rare cause of pulmonary hypertension in newborns. Maternally inherited point mutations in Forkhead Box F1 gene (FOXF1), deletions of the gene, or its long-range enhancers on the maternal allele are responsible for this neonatal lethal disorder. Here, we describe monozygotic twins and one full-term newborn with ACD and gastrointestinal malformations caused by de novo mutations of FOXF1 on the maternal-inherited alleles. Since this parental transmission is consistent with genomic imprinting, the parent-of-origin specific monoallelic expression of genes, we have undertaken a detailed analysis of both allelic expression and DNA methylation. FOXF1 and its neighboring gene FENDRR were both biallelically expressed in a wide range of fetal tissues, including lung and intestine. Furthermore, detailed methylation screening within the 16q24.1 regions failed to identify regions of allelic methylation, suggesting that disrupted imprinting is not responsible for ACDMPV.

A Novel De Novo Pathogenic Variant in FOXF1 in a Newborn with Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins.

Abstract: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is an autosomal dominant, fatal developmental disorder of the lungs, with a mortality rate of about 100%. ACD/MPV is caused by mutations in FOXF1. Herein, we describe a newborn boy with ACD/MPV carrying a novel pathogenic variant of FOXF1. The patient developed respiratory distress and severe pulmonary hypertension on the first day of life. Despite aggressive cardiorespiratory management, including veno-venous extracorporeal membrane oxygenation, his condition deteriorated rapidly, and he died within the first month of his life. Lung histology showed the characteristic features of ACD/MPV at autopsy. Sequence analysis of FOXF1 from genomic DNA obtained from autopsied lung tissue revealed that the patient was heterozygous for a novel missense variant (c.305T>C; p.Leu102Pro). Further analysis of both parents confirmed the de novo occurrence of the variant. To the best of our knowledge, this is the first report of genetically confirmed ACD/MPV in Korea.

Antenatal gastrointestinal anomalies in neonates subsequently found to have alveolar capillary dysplasia.

Abstract: Alveolar capillary dysplasia (ACD) is a rare condition with variable presentation and clinical course. Clinicians should consider this diagnosis in neonates presenting with nonlethal congenital gastrointestinal malformation, a period of well-being after birth then unremitting hypoxemia and refractory pulmonary hypertension. Lung biopsy and FOXF1 gene testing may help in diagnosis.

Congenital Alveolar Capillary Dysplasia and New Associations: A CaseSeries with a Report of New Associations and Literature Review

Abstract: Congenital Alveolar capillary dysplasia with misalignment of the pulmonary veins (ACD-MPV) is a rare and a lethal cause of neonatal respiratory failure and severe hypoxemia, secondary to persistent pulmonary hypertension (PPHN). It is refractory to all standard medical therapies including High Frequency Ventilation (HFV), inspired Nitric Oxide (iNO), and Extracorporeal Membrane Oxygenation (ECMO). According to the Online Mendelian Inheritance in Man (OMIM), it is caused by heterozygous mutation in the FOXF1 gene on chromosome 16q24. Newer study has suggested that two other genes can cause (ESRP1) or function as modifiers (PLXNB2) of the ACDMPV phenotype. Most reported cases of ACD-MPV had multiple congenital non-lethal anomalies. Here, we report six cases of autopsyproven ACD-MPV from a single institution during a seven year period. Medical information was obtained from the electronic medical records. Pathology slides were read and confirmed by pediatric pathologists of two different university hospitals. Novel findings include an association with previously undescribed congenital anomalies and a sibling with congenital alveolar dysplasia without capillary dysplasia. All patients presented in the newborn period, with severe hypoxemia and echocardiogram (Echo)-confirmed PPHN. The vast majority of ACDMPV cases continue to be diagnosed by autopsy, after the infants have been subjected to extreme degree of intensive care. ACD-MPV needs to be considered as a diagnostic possibility when ECMO fails.