Filamin A (FLNA) mutation-A newcomer to the childhood interstitial lung disease (ChILD) classification

Pulmonary fibrosis may begin in infancy: from childhood to adult interstitial lung disease

BACKGROUND

Childhood interstitial lung disease (chILD) encompasses a group of rare heterogeneous respiratory conditions associated with significant morbidity and mortality. Reports suggest that many patients diagnosed with chILD continue to have potentially progressive or fibrosing disease into adulthood. Over the last decade, the spectrum of conditions within chILD has widened substantially, with the discovery of novel entities through advanced genetic testing. However, most evidence is often limited to small case series, with reports disseminated across an array of subspecialty, clinical and molecular journals. In particular, the frequency, management and outcome of paediatric pulmonary fibrosis is not well characterised, unlike in adults, where clear diagnosis and treatment guidelines are available.

METHODS AND RESULTS

This review assesses the current understanding of pulmonary fibrosis in chILD. Based on registry data, we have provisionally estimated the occurrence of fibrosis in various manifestations of chILD, with 47 different potentially fibrotic chILD entities identified. Published evidence for fibrosis in the spectrum of chILD entities is assessed, and current and future issues in management of pulmonary fibrosis in childhood, continuing into adulthood, are considered.

CONCLUSIONS

There is a need for improved knowledge of chILD among pulmonologists to optimise the transition of care from paediatric to adult facilities. Updated evidence-based guidelines are needed that incorporate recommendations for the diagnosis and management of immune-mediated disorders, as well as chILD in older children approaching adulthood.

Interstitial lung disease as an indication for pediatric lung transplant

Interstitial lung disease can be an indication for lung transplant at any age, but it is a particularly common indication for lung transplant in infants. Nevertheless, not all interstitial lung diseases will lead to lung transplant in childhood. Genetic testing has aided the identification of these diseases in children. In severely affected patients, however, definitive diagnosis is not always necessary to consider referral to a transplant center. At experienced transplant centers, a multidisciplinary team educates patient families and aids in the transplant evaluation of children with interstitial lung disease. Children who have undergone transplant require lifetime immunosuppression and close surveillance, but can enjoy good quality of life for years following surgery.

Childhood interstitial lung diseases: current understanding of the classification and imaging findings

Childhood interstitial lung diseases (chILDs) encompass a diverse group of disorders with a high mortality rate and severe respiratory morbidities. Recent investigations have revealed that the classification of adult ILDs is not valid for chILDs, particularly for ILDs of early onset. Therefore, Children's Interstitial Lung Disease Research Cooperative of North America proposed a new classification of chILDs for affected children under 2 years of age, and later another classification for affected individuals between 2 and 18 years of age. In this review, we provide an overview of the imaging findings of chILDs by classification. Most infantile ILDs have unique clinical, radiological, and molecular findings, while the manifestation of pediatric ILDs overlaps with that of adult ILDs.

Advancements in imaging in ChILD

Interstitial and diffuse lung diseases in children constitute a range of congenital and acquired disorders. These disorders present with signs and symptoms of respiratory disease accompanied by diffuse radiographic changes. In many cases, radiographic findings are nonspecific, while in other disorders, chest computed tomography (CT) is diagnostic in the appropriate context. Regardless, chest imaging remains central in the evaluation of the patient with suspected childhood interstitial lung disease (chILD). Several newly described chILD entities, spanning both genetic and acquired etiologies, have imaging that aid in their diagnoses. Advances in CT scanning technology and CT analysis techniques continue to improve scan quality as well as expand use of chest CT as a research tool. Finally, ongoing research is expanding use of imaging modalities without ionizing radiation. Magnetic resonance imaging is being applied to investigate pulmonary structure and function, and ultrasound of the lung and pleura is a novel technique with an emerging role in chILD disorders. This review describes the current state of imaging in chILD including recently described diagnoses, advances in conventional imaging techniques and applications, and evolving new imaging modalities that expand the clinical and research roles for imaging in these disorders.

Interstitial lung disease in the newborn

Although relatively rare, interstitial lung diseases may present with respiratory distress in the newborn period. Most commonly these include developmental and growth disorders, disorders of surfactant synthesis and homeostasis, pulmonary interstitial glycogenosis, and neuroendocrine cell hyperplasia of infancy. Although the diagnosis of these disorders is sometimes made based on clinical presentation and imaging, due to the significant overlap between disorders and phenotypic variability, lung biopsy or, increasingly genetic testing is needed for diagnosis. These diseases may result in significant morbidity and mortality. Effective medical treatment options are in some cases limited and/or invasive. The genetic basis for some of these disorders has been identified, and with increased utilization of exome and whole genome sequencing even before lung biopsy, further insights into their genetic etiologies should become available.

Neonatal and Infant Lung Disorders: Glossary, Practical Approach, and Diagnoses

A multitude of lung disorders ranging from congenital and genetic anomalies to iatrogenic complications can affect the neonate or the infant within the first year of life. Neonatal and infant chest imaging, predominantly by plain radiography and computed tomography, is frequently employed to aid in diagnosis and management; however, these disorders can be challenging to differentiate due to their broad-ranging, and frequently overlapping radiographic features. A systematic and practical approach to imaging interpretation which includes recognition of radiologic patterns, utilization of commonly accepted nomenclature and classification, as well as interpretation of imaging findings in conjunction with clinical history can not only assist radiologists to suggest the diagnosis, but also aid clinicians in management planning. The contents of this article were endorsed by the leadership of both the World Federation of Pediatric Imaging (WFPI), and the International Society of Pediatric Thoracic Imaging (ISPTI).

Subpleural pulmonary cysts in children: Associations beyond Trisomy 21

BACKGROUND

Small air-filled peripheral subpleural cysts are a well-described feature of pulmonary anatomy at computerized tomographic (CT) scan in children with Trisomy 21, yet only anecdotally described in association with other pathologies. The significance of these cysts is unknown.

OBJECTIVE

To investigate and explore the pathogenesis of these subpleural cysts in children.

MATERIALS AND METHODS

A retrospective review of 16 cases with subpleural cysts diagnosed on CT chest was performed. The distribution, location, and ancillary CT findings were recorded. Hospital charts were reviewed for clinical details, especially cardiac abnormalities, pulmonary artery hypertension (PAH) and genetic associations. Histopathological and clinical correlative data were recorded.

RESULTS

Eleven of the 16 children (69%) were found to have an underlying chromosomal or genetic abnormality, six of whom had Trisomy 21. The remaining 5 of the 16 cases (21%) had miscellaneous disorders without an identifiable genetic basis. The most common co-morbidities were cardiac abnormalities (81%) and PAH (62.5%). Regardless of their underlying etiologies, the cysts were present bilaterally in most cases (14/16, 88%). We observed both the postnatal development and the progression of cysts in our cohort. On long-term follow-up, there were five deaths (31%) and six cases (38%) requiring maintenance oxygen therapy due to chronic hypoxia. Two cases (12.5%) became completely asymptomatic after correction of their underlying abnormalities.

CONCLUSION

Subpleural cysts are not exclusive to Trisomy 21 and may be seen in other inherited or acquired causes, likely due to altered alveolar growth. We suspect these cysts are a sign of an underlying developmental disorder with variable clinical effect, especially in children with congenital cardiac disease.

Childhood Interstitial Lung Disease

Childhood interstitial lung disease (chILD) is a heterogeneous group of diseases with various clinical and imaging findings. The incidence and prevalence have increased in recent years, probably due to better comprehension of these rare diseases and increased awareness among physicians. chILDs present with nonspecific pulmonary symptoms, such as tachypnea, hypoxemia, cough, rales, and failure to thrive. Unnecessary invasive procedures can be avoided if specific mutations are detected through genetic examinations or if typical imaging patterns are recognized on computed tomography. Disease knowledge and targeted therapies are improving through international collaboration. Pulmonary involvement in systemic diseases is not uncommon. Pulmonary involvement may be the first finding in connective tissue diseases. This review aims to present a systematic patient-targeted approach to the diagnosis of chILD.

Diagnostic workup of childhood interstitial lung disease

Childhood interstitial lung diseases (chILDs) are rare and heterogeneous diseases with significant morbidity and mortality. An accurate and quick aetiological diagnosis may contribute to better management and personalised treatment. On behalf of the European Respiratory Society Clinical Research Collaboration for chILD (ERS CRC chILD-EU), this review summarises the roles of the general paediatrician, paediatric pulmonologists and expert centres in the complex diagnostic workup. Each patient's aetiological chILD diagnosis must be reached without prolonged delays in a stepwise approach from medical history, signs, symptoms, clinical tests and imaging, to advanced genetic analysis and specialised procedures including bronchoalveolar lavage and biopsy, if necessary. Finally, as medical progress is fast, the need to revisit a diagnosis of "undefined chILD" is stressed.

Heterogenous Disease Course and Long-Term Outcome of Children's Interstitial Lung Disease Related to Filamin A Gene Variants

Rationale: Variable disease course and outcomes have been reported in children's interstitial lung disease associated with FLNA (Filamin A gene) variants. Objectives: To further delineate long-term respiratory outcomes and identify potential contributing factors to severe disease course. Methods: We retrospectively collected longitudinal data from three centers on nine cases (one male) with FLNA variants and early respiratory disease onset (within the first 24 mo of life). Clinical, radiographic, and histopathologic data were analyzed, focusing on cardiorespiratory disease course. Results: All required early respiratory support (three invasive ventilation, three noninvasive ventilation, three supplemental oxygen), and all experienced frequent severe infective respiratory exacerbations. Three died in infancy from refractory respiratory failure and pulmonary hypertension (PH). The six surviving individuals were 3, 10, 11, 15, 18, and 33 years old at time of reporting. The extent of functional respiratory impairment decreased with age; at last follow-up, there were no individuals on home invasive ventilation, one on nocturnal noninvasive ventilation, four on oxygen, and one on no respiratory support. Spirometry consistently demonstrated moderate to severe obstructive defects (forced expiratory volume in 1 s/forced vital capacity [FVC] z-score, -3.76 to -1.77; percent predicted FVC, 31.5% to 92.1%). Seven required PH treatment in early childhood (7/9), and three of the survivors (3/6) still receive treatment. Radiologic and histopathologic findings were consistent among cases. Conclusions: Early mortality was common, but many survivors stabilized even after severe symptoms in infancy. All survivors had persistent obstructive defects on spirometry, and half have persistent or recurrent PH. These typical findings are suggestive of this rare diagnosis and should prompt consideration of genetic testing.

Childhood interstitial lung disease more prevalent in infancy: a practical review

Childhood interstitial lung disease (chILD) is a heterogeneous group of uncommon, mostly chronic pediatric pulmonary disorders characterized by impaired gas exchange and diffuse abnormalities on imaging. A subset of these diseases occurs more frequently in infants and young children than in older children and teenagers. Some of these disorders occur in certain clinical scenarios and/or have typical imaging features that can help the radiologist recognize when to suggest a possible diagnosis and potentially spare a child a lung biopsy. We review the clinical, histopathological and computed tomography features of chILD more prevalent in infancy, including diffuse developmental disorders, growth abnormalities, specific conditions of undefined etiology, and surfactant dysfunction mutations and related disorders, to familiarize the pediatric radiologist with this group of disorders.

Congenital lung lesions: a radiographic pattern approach

Congenital lung malformations represent a spectrum of abnormalities that can overlap in imaging appearance and frequently coexist in the same child. Imaging diagnosis in the neonatal period can be challenging; however, the recognition of several archetypal radiographic patterns can aid in narrowing the differential diagnosis. Major radiographic archetypes include (1) hyperlucent lung, (2) pulmonary cysts, (3) focal opacity and (4) normal radiograph. Here we review the multimodality imaging appearances of the most commonly seen congenital lung malformations, categorized by their primary imaging archetypes. Along with the congenital lung malformations, we present several important imaging mimickers.

Cardiovascular, Brain, and Lung Involvement in a Newborn With a Novel FLNA Mutation: A Case Report and Literature Review

BACKGROUND

Filamin A (FLNA) is an intracellular actin-binding protein, encoded by the FLNA gene, with a wide tissue expression. It is involved in several cellular functions, and extracellular matrix structuring. FLNA gene alterations lead to diseases with a wide phenotypic spectrum, such as brain periventricular nodular heterotopia (PVNH), cardiovascular abnormalities, skeletal dysplasia, and lung involvement.

CLINICAL FINDINGS

We present the case of a female infant who showed at birth aortic valve stenosis and PVNH, and subsequently developed interstitial lung disease with severe pulmonary hypertension.

PRIMARY DIAGNOSIS

The association of aortic valve dysplasia, left ventricular outflow obstruction, persistent patent ductus arteriosus, and brain heterotopic gray matter suggested a possible FLNA gene alteration. A novel heterozygous intronic variant in the FLNA gene (NM_001110556.1), c.4304-1G >A, was detected.

INTERVENTIONS

In consideration of valve morphology and severity of stenosis, the neonate was scheduled for a transcatheter aortic valvuloplasty. At 3 months of life, she developed hypoxemic respiratory failure with evidence of severe pulmonary hypertension. Inhaled nitric oxide (iNO) and milrinone on continuous infusion were started. Because of a partial response to iNO, an intravenous continuous infusion of sildenafil was introduced.

OUTCOMES

In consideration of severe clinical course and fatal outcome, the new FLNA gene mutation described in our patient seems to be associated with a loss of function of FLNA.

PRACTICE RECOMMENDATIONS

Lung and brain involvement, in association with left ventricular outflow obstruction and persistent patency of ductus arteriosus, should be considered highly suggestive of FLNA gene alterations, in a female newborn.

Platelet function and filamin A expression in two families with novel FLNA gene mutations associated with periventricular nodular heterotopia and panlobular emphysema

Pathogenic variants of the X‐linked FLNA gene encoding filamin A protein have been associated with a wide spectrum of symptoms, including the recently described pulmonary phenotype with childhood‐onset panlobular emphysema. We describe three female patients from two families with novel heterozygous FLNA variants c.5837_2del and c.508C > T. Analysis of immunofluorescence of peripheral blood smears and platelet function was performed for all patients. FLNA‐negative platelets were observed, suggesting that these variants result in the loss of a functional protein product. All three patients also had periventricular nodular heterotopia and panlobular emphysema. However, they had considerably milder symptoms and later age of onset than in the previously reported cases. Therefore, patients with pathogenic FLNA variants should be studied actively for lung involvement even in the absence of pronounced respiratory symptoms. Conversely, any patient with unexplained panlobular emphysema should be analyzed for pathogenic FLNA variants. We also suggest that immunofluorescence analysis is a useful tool for investigating the pathogenicity of novel FLNA variants.

Application of lung volume reduction surgery for a child with filamin A (FLNA) mutations

Diffuse lung disease in early childhood due to mutations in the filamin A gene has been recently reported. Clinical outcomes vary among individuals indicating variability in phenotype but a substantial proportion of reported cases in early life have ended up in death or lung transplantation. We recently encountered a school-aged child in whom the diagnosis of a filamin A mutation was delayed and the natural history of emphysematous lung disease was altered by serial lung volume reduction surgeries. She eventually underwent a bilateral lung transplant and we report the natural history of her disease and treatments applied herein.

Childhood Interstitial Lung Disease: Imaging Guidelines and Recommendations

Childhood interstitial lung disease (ChILD) is an umbrella term encompassing a diverse group of diffuse lung diseases affecting infants and children. Although the timely and accurate diagnosis of ChILD is often challenging, it is optimally achieved through the multidisciplinary integration of imaging findings with clinical data, genetics, and potentially lung biopsy. This article reviews the definition and classification of ChILD; the role of imaging, pathology, and genetics in ChILD diagnosis; treatment options; and future goals. In addition, a practical approach to ChILD imaging based on the latest available research and the characteristic imaging appearance of ChILD entities are presented.

Heterogeneous Pulmonary Phenotypes in Filamin A Mutation-Related Lung Disease

Background: Interstitial lung disease (ILD) has been recently reported in a few patients with pathogenic variants in the Filamin A (FLNA) gene with variable presentation and prognosis. This study evaluated the respiratory manifestations and clinical features in children with FLNA disease. Methods: We conducted a retrospective review of pediatric patients with variants in FLNA in a tertiary children's hospital. The clinical features, genotype, management, and outcomes were analyzed. Results: We identified 9 patients with variants in FLNA aged 15 months to 24 years, 4 females and 5 males. Six patients had abnormal chest imaging ranging from mild interstitial prominence to atelectasis, interstitial densities, and hyperinflation. Three patients with ILD presented during the neonatal period or early infancy with respiratory distress or respiratory failure requiring supplemental oxygen or assisted ventilation via tracheostomy. We report male twins with the same FLNA variant and lung disease, but different ages and clinical features at presentation eventually culminating in respiratory failure requiring assisted ventilation. All patients had FLNA variants identified by FLNA sequencing, had abnormal echocardiograms, and none of the patients underwent lung biopsy or lung transplantation. The outcomes were variable and could be as severe as chronic respiratory failure. Conclusion: The wide spectrum of respiratory manifestations and abnormal chest imaging in our study highlights the importance of evaluation for lung disease in patients with variants in FLNA. FLNA sequencing in suspected cases with ILD may obviate the need for a lung biopsy, prompt surveillance for progressive lung disease, and evaluation for associated clinical features.

Pulmonary growth abnormalities as etiologies for pediatric pulmonary hypertension

Pulmonary growth abnormality (PGA) is a common type of diffuse lung disease in infants. Although the histologic and radiographic features of PGA have been described in the literature in varying detail, the clinical spectrum of disease has not. The array of case series and case reports has led to a clinical picture that could be confusing to clinicians. We describe three subsets of PGA, including its association with the histologic marker of pulmonary interstitial glycogenosis, and its common association with pulmonary hypertension. We propose a new approach to what we consider an increasingly broad array of different disease entities.

Filamin A Mutations: A New Cause of Unexplained Emphysema in Adults?

Emphysema is a chronic respiratory disorder characterized by destruction of alveoli, usually due to cigarette smoking or exposure to noxious particles or gases. Dysfunction of proteins that are involved in lung development and maintenance, such as alpha-1 antitrypsin, also contributes to emphysema. Filamin A (FLNA) is an actin-binding protein involved in cytoskeleton reorganization. Mutations in the FLNA gene classically lead to abnormal neuronal migration and connective and vascular tissue anomalies. Pulmonary manifestations consist of a wide range of pulmonary disorders that occur during infancy. We report the first familial case of emphysema in non- and very low-smoking adults who carry a loss-of-function mutation of the FLNA gene. The identification of this new risk factor for emphysema encourages (1) screening, prevention and monitoring of pulmonary disorders in patients with FLNA mutation and (2) screening for FLNA mutation in patients with early-onset emphysema that is associated with low-smoking or vascular or connective tissue anomalies.

Where the congenital heart disease meets the pulmonary arterial hypertension, FLNA matters: a case report and literature review

Background

Pediatric patients with genetic disorders have a higher incidence of pulmonary arterial hypertension (PAH) regardless of their heart defects. Filamin A (FLNA) mutation is recently recognized to be associated with pediatric pulmonary disorders, however, the clinical courses of PAH related to the mutation were reported in limited cases. Here, we presented a case and pooled data for better understanding of the correlation between FLNA mutation and pediatric PAH.

Case presentation

The patient was a 8-month-old female with repeated episodes of pneumonia. Physical examination revealed cleft lip, cleft palate and developmental retardation. Imaging examination showed a small atrial septal defect (ASD), central pulmonary artery enlargement, left upper lobe of lung atelectasis, and pulmonary infiltration. Genetic test showed she carried a de novo pathogenic variant of FLNA gene (c.5417-1G > A, p.-). Oral medications didn’t slow the progression of PAH in the patient, and she died two years later.

Conclusions

FLNA mutation causes rare but progressive PAH in addition to a wide spectrum of congenital heart disease and other comorbidities in pediatric patients. We highly recommend genetic testing for pediatric patients when suspected with PAH. Given the high mortality in this group, lung transplantation may offer a better outcome.

Interstitial lung disease in infancy

There is a wide differential diagnosis of early onset respiratory distress especially in term babies, and interstitial lung disease (chILD) is a rare but important consideration in this context. chILD manifesting immediately after birth is usually related to mutations in surfactant protein genes, or conditions related to the Congenital Acinar Dysplasia -Alveolar capillary dysplasia - Congenital Alveolar Dysplasia (CAD-ACD) spectrum. There is currently no specific treatment for these conditions, and management is supportive. Prognosis is very poor in most of these babies if onset is early, with relentless respiratory deterioration unless transplanted. Ideally, the diagnosis is made on genetic analysis, but this may be time-consuming and complex in CAD-ACD spectrum, so lung biopsy may be needed to avoid prolonged and futile treatment being instituted. Milder forms with prolonged survival have been reported. Early onset, less severe chILD is usually related to neuroendocrine cell hyperplasia of infancy (NEHI), pulmonary interstitial glycogenosis (PIG) and less severe disorders of surfactant proteins. PIG and NEHI are not specific entities, but are pulmonary dysmaturity syndromes, and there may be a number of underlying genetic and other cause. If the child is stable and thriving, many will not be subject to lung biopsy, and slow improvement and weaning of supplemental oxygen can be anticipated. Where possible, a precise genetic diagnosis should be made in early onset cHILD allow for genetic counselling. chILD survivors and their families have complex respiratory and other needs, and co-ordinated, multi-disciplinary support in the community is essential.

Interstitial lung diseases in children

Interstitial lung disease (ILD) in children (chILD) is a heterogeneous group of rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality. The pathogenesis of the various chILD is complex and the diseases share common features of inflammatory and fibrotic changes of the lung parenchyma that impair gas exchanges. The etiologies of chILD are numerous. In this review, we chose to classify them as ILD related to exposure/environment insults, ILD related to systemic and immunological diseases, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. A growing part of the etiologic spectrum of chILD is being attributed to molecular defects. Currently, the main genetic mutations associated with chILD are identified in the surfactant genes SFTPA1, SFTPA2, SFTPB, SFTPC, ABCA3 and NKX2-1. Other genetic contributors include mutations in MARS, CSF2RA and CSF2RB in pulmonary alveolar proteinosis, and mutations in TMEM173 and COPA in specific auto-inflammatory forms of chILD. However, only few genotype-phenotype correlations could be identified so far. Herein, information is provided about the clinical presentation and the diagnosis approach of chILD. Despite improvements in patient management, the therapeutic strategies are still relying mostly on corticosteroids although specific therapies are emerging. Larger longitudinal cohorts of patients are being gathered through ongoing international collaborations to improve disease knowledge and targeted therapies. Thus, it is expected that children with ILD will be able to reach the adulthood transition in a better condition.

Blood co-expression modules identify potential modifier genes of diabetes and lung function in cystic fibrosis

Cystic fibrosis (CF) is a rare genetic disease that affects the respiratory and digestive systems. Lung disease is variable among CF patients and associated with the development of comorbidities and chronic infections. The rate of lung function deterioration depends not only on the type of mutations in CFTR, the disease-causing gene, but also on modifier genes. In the present study, we aimed to identify genes and pathways that (i) contribute to the pathogenesis of cystic fibrosis and (ii) modulate the associated comorbidities. We profiled blood samples in CF patients and healthy controls and analyzed RNA-seq data with Weighted Gene Correlation Network Analysis (WGCNA). Interestingly, lung function, body mass index, the presence of diabetes, and chronic P. aeruginosa infections correlated with four modules of co-expressed genes. Detailed inspection of networks and hub genes pointed to cell adhesion, leukocyte trafficking and production of reactive oxygen species as central mechanisms in lung function decline and cystic fibrosis-related diabetes. Of note, we showed that blood is an informative surrogate tissue to study the contribution of inflammation to lung disease and diabetes in CF patients. Finally, we provided evidence that WGCNA is useful to analyze–omic datasets in rare genetic diseases as patient cohorts are inevitably small.

Childhood Interstitial (Diffuse) Lung Disease: Pattern Recognition Approach to Diagnosis in Infants

OBJECTIVE. The purpose of this article is to discuss imaging techniques and a pattern-based approach for diagnosing childhood interstitial (diffuse) lung diseases in infants. CONCLUSION. Childhood interstitial (diffuse) lung disease in infants consists of a heterogeneous group of disorders previously classified with clinical, radiologic, and pathologic features. By use of an imaging-guided algorithm, the assessment of lung volumes and the presence of ground-glass opacities or cysts can assist the radiologist in making an accurate and timely diagnosis.

Microdeletion in Xq28 with a polymorphic inversion in a patient with FLNA-associated progressive lung disease

Lung phenotype was reported as a novel phenotype in patients with mutations in the filamin A gene (FLNA) in 2011. FLNA mutations can result in pulmonary hyperinflation during the neonatal period or early infancy with progressive respiratory failure, culminating in a diagnosis of FLNA-associated progressive lung disease, particularly if the patient has periventricular nodular heterotopia and cardiac complications, such as patent ductus arteriosus, atrial septal defect, and pulmonary hypertension. We report the first Japanese case of FLNA-associated progressive lung disease caused by a microdeletion in Xq28 encompassing the FLNA gene with a polymorphic inversion.

Congenital emphysematous lung disease associated with a novel Filamin A mutation. Case report and literature review

BACKGROUND

Progressive lung involvement in Filamin A (FLNA)-related cerebral periventricular nodular heterotopia (PVNH) has been reported in a limited number of cases.

CASE PRESENTATION

We report a new pathogenic FLNA gene variant (c.7391_7403del; p.Val2464Alafs*5) in a male infant who developed progressive lung disease with emphysematous lesions and interstitial involvement. Following lobar resection, chronic respiratory failure ensued necessitating continuous mechanical ventilation and tracheostomy. Cerebral periventricular nodular heterotopia was also present.

CONCLUSIONS

We report a novel variant of the FLNA gene, associated with a severe lung disorder and PNVH. The lung disorder led to respiratory failure during infancy and these pulmonary complications may be the first sign of this disorder. Early recognition with thoracic imaging is important to guide genetic testing, neuroimaging and to define optimal timing of potential therapies, such as lung transplant in progressive lung disease.

Building and Regenerating the Lung Cell by Cell

The unique architecture of the mammalian lung is required for adaptation to air breathing at birth and thereafter. Understanding the cellular and molecular mechanisms controlling its morphogenesis provides the framework for understanding the pathogenesis of acute and chronic lung diseases. Recent single-cell RNA sequencing data and high-resolution imaging identify the remarkable heterogeneity of pulmonary cell types and provides cell selective gene expression underlying lung development. We will address fundamental issues related to the diversity of pulmonary cells, to the formation and function of the mammalian lung, and will review recent advances regarding the cellular and molecular pathways involved in lung organogenesis. What cells form the lung in the early embryo? How are cell proliferation, migration, and differentiation regulated during lung morphogenesis? How do cells interact during lung formation and repair? How do signaling and transcriptional programs determine cell-cell interactions necessary for lung morphogenesis and function?

A review of filamin A mutations and associated interstitial lung disease

The filamin A gene (FLNA) on Xq28 encodes the filamin A protein. Mutation in FLNA causes a wide spectrum of disease including skeletal dysplasia, neuronal migration abnormality, cardiovascular malformation, intellectual disability and intestinal obstruction. Recently, childhood-onset interstitial lung disease associated with a range of FLNA mutations has been recognised and reported. We document our personal experience of this emerging disorder and compile a comprehensive overview of clinical features and molecular changes in all identifiable published cases. Reviewing the emerging dataset, we underline this unanticipated phenotypic consequence of pathogenic FLNA mutation-associated pulmonary disease.Conclusion: From the emerging data, we suggest that while reviewing complex cases with a sustained oxygen requirement against a clincial background of cardiac concerns or intestinal obstruction to have a high index of suspicion for FLNA related pathology and to instigate early MRI brain scan and FLNA mutation analysis. What is Known: • FLNA gene on Xq28 encodes the filamin A protein and mutation therein is associated with variable phenotypes depending on its nature of mutation. • Loss-of-function mutation of filamin A is associated with X-linked inherited form of periventricular nodular heterotopia with or without epilepsy with most individuals affected being female. There is a recently recognised associated respiratory phenotype. What is New: • The respiratory phenotype in the form of childhood interstitial lung disease is a recently recognised clinical consequence of loss-of-function FLNA mutation. • Rare male patients with loss-of-function FLNA mutation-associated lung disease with residual protein function can survive into infancy with a severe form of the phenotype.

Pediatric pulmonology year in review 2017: Part 1

Pediatric Pulmonology publishes original research, case reports and review articles on topics related to a wide range of children's respiratory disorders. In this article (Part 1 of a series), we summarize the past year's publications in our major topic areas, as well as selected literature in these areas from other journals. In Part 1, we review selected articles on diagnostic testing/endoscopy, respiratory complications of neuromuscular disorders, and rare lung diseases.

Chronic interstitial lung diseases in children: diagnosis approaches

Introduction: Children interstitial lung disease (chILD) is a heterogeneous group of rare respiratory disorders characterized by inflammatory and fibrotic changes of the lung parenchyma. They include ILD related to exposure/environment insults, ILD related to systemic diseases processes, ILD related to primary lung parenchyma dysfunctions and ILD specific to infancy. Areas covered: This review provides an update on chILD pathophysiology and diagnosis approaches in immunocompetent children. It includes current information on genetic causes. Expert commentary: ChILD covers a large spectrum of entities with heterogeneous disease expression. Various classifications have been reported, but none of them seems completely satisfactory. Recently, progress in molecular genetics has allowed identifying some genetic contributors, with, so far, a lack of correlations between gene disorders and disease expression. Despite improvements in patient management, chILD prognosis is still burdened by significant morbidity and mortality. Ongoing international collaborations will allow gathering larger longitudinal cohorts of patients to improve disease knowledge and personalized care. The overall goal is to help the children with ILD to reach the adulthood transition in a better condition, and to structure genetic counseling for their family.

Comprehensive analysis of metastasis-related genes reveals a gene signature predicting the survival of colon cancer patients

Objective

The mechanism underlying colon cancer metastasis remain unclear. This study aimed to elucidate the genes alteration during the metastasis of colon cancer and identify genes that crucial to the metastasis and survival of colon cancer patients.

Methods

The dataset of primary and metastasis tissue of colon cancer, and dataset of high and low metastasis capability of colon cancer cells were selected as training cohort, and the overlapped differentially expressed genes (DEGs) were screened from the training cohort. The functional enrichment analysis for the overlapped DEGs was performed. The prognostic value of overlapped DEGs were analyzed in The Cancer Genome Atlas dataset, and a gene signature was developed using genes that related to the overall survival (OS). The prognostic value of the gene signature was further confirmed in a validation cohort.

Results

A total of 184 overlapped DEGs were screened from the training cohort. Functional enrichment analysis revealed the significant gene functions and pathways of the overlapped DEGs. Four hub genes (3-oxoacid CoA-transferase 1, actinin alpha 4, interleukin 8, integrin subunit alpha 3) were identified using protein–protein network analysis. Six genes (aldehyde dehydrogenase 2, neural precursor cell expressed, developmentally down-regulated 9, filamin A, lamin B receptor, twinfilin actin binding protein 1, serine and arginine rich splicing factor 1) were closely related to the OS of colon cancer patients. A gene signature was developed using these six genes based on their risk score, and the validation cohort indicated that the prognostic value of this gene signature was high in the prediction of colon cancer patients.

Conclusions

Our study demonstrates a gene profiles related to the metastasis of colon cancer, and identify a six-gene signature that acts as an independent biomarker on the prognosis of colon cancer.