Variants in FGF10 cause early onset of severe childhood interstitial lung disease: A detailed description of four affected children

Pediatric Pulmonology 2023 year in review: Rare and diffuse lung disease

The field of pediatric rare and diffuse lung disease continues its maturation as research advances the understanding of diagnosis and treatment of children's interstitial lung disease, noncystic fibrosis bronchiectasis, and primary ciliary dyskinesia. The rarity and breadth of these conditions make them challenging to study, yet we continue to make progress in our understanding of pathophysiology, genotype/phenotype relationships, and treatment. Papers published on these topics in Pediatric Pulmonology and other journals in 2023 describe the power of multicenter cooperation and patient registries, enhance our understanding of pathophysiology and genotype/phenotype relationships, and report progress in treatments. In this review, we hope to increase awareness and knowledge of these conditions and to inspire future research.

Fibrotic lung diseases in children

In children, pulmonary fibrosis (PF) is an extremely unusual entity that can be observed in some types of interstitial lung disease (ILD). Defining whether ILD is accompanied by PF is important for targeted therapy. Algorithm for the diagnosis of PF in children is not clearly established. Besides, the clinical, radiological, and histological definitions commonly used to diagnose particularly the cases of idiopathic PF in adult patients, is not applicable to pediatric cases. However, a few studies conducted in children offer good exemplary diagnostic approach to fibrosing ILD. Thorax high resonance computed tomography and/or lung biopsy scanning can provide valuable information about PF. Another issue that has not been clearly established is when to start antifibrotic treatment in pediatric patients with PF. The objective of this current review is to provide a comprehensive overview of pediatric PF by drawing upon adult research, particularly focusing on the areas of uncertainty.

Pulmonary Hypertension in Developmental Lung Diseases

Diverse genetic developmental lung diseases can present in the neonatal period with hypoxemic respiratory failure, often associated with with pulmonary hypertension. Intractable hypoxemia and lack of sustained response to medical management should increase the suspicion of a developmental lung disorder. Genetic diagnosis and lung biopsy are helpful in establishing the diagnosis. Early diagnosis can result in optimizing management and redirecting care if needed. This article reviews normal lung development, various developmental lung disorders that can result from genetic abnormalities at each stage of lung development, their clinical presentation, management, prognosis, and differential diagnoses.

Fibroblast growth factor 10

Fibroblast growth factor 10 (FGF10) is a major morphoregulatory factor that plays essential signaling roles during vertebrate multiorgan development and homeostasis. FGF10 is predominantly expressed in mesenchymal cells and signals though FGFR2b in adjacent epithelia to regulate branching morphogenesis, stem cell fate, tissue differentiation and proliferation, in addition to autocrine roles. Genetic loss of function analyses have revealed critical requirements for FGF10 signaling during limb, lung, digestive system, ectodermal, nervous system, craniofacial and cardiac development. Heterozygous FGF10 mutations have been identified in human genetic syndromes associated with craniofacial anomalies, including lacrimal and salivary gland aplasia. Elevated Fgf10 expression is associated with poor prognosis in a range of cancers. In addition to developmental and disease roles, FGF10 regulates homeostasis and repair of diverse adult tissues and has been identified as a target for regenerative medicine.