Genetic basis for childhood interstitial lung disease among Japanese infants and children

Background: Genetic variants responsible for childhood interstitial lung disease (chILD) have not been studied extensively in Japanese patients. Methods: The study population consisted of 62 Japanese chILD patients. Twenty-one and four patients had pulmonary hypertension resistant to treatment (PH) and hypothyroidism, respectively. Analyses of genetic variants were performed in all 62 patients for SFTPC and ABCA3, in all 21 PH patients for FOXF1, and in a limited number of patients for NKX2.1. Results: Causative genetic variants for chILD were identified in 11 (18%) patients: SFTPC variants in six, NKX2.1 variants in three, and FOXF1 variants in two patients. No patients had ABCA3 variants. All three and two patients with NKX2.1 variants had hypothyroidism and developmental delay, respectively. We found six novel variants in this study. Conclusion: Mutations in SFTPC, NKX2.1, and FOXF1 were identified among Japanese infants and children with chILD, whereas ABCA3 mutations were rare.