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Mutations in genes critical for surfactant metabolism, including surfactant protein C ( SP- C) and ABCA3, are well-recognized causes of interstitial lung disease. Recessive mutations in ABCA3 were first attributed to fatal respiratory failure in full-term neonates, but they are also increasingly being recognized as a cause of respiratory disorders with less severe phenotypes in older children and also adults. Here, we report a 20-month-old boy with interstitial lung disease caused by two distinct ABCA3 mutations. Initial treatment with methylprednisolone was unsuccessful, but the additional administration of hydroxychloroquine was effective. The family history revealed that the patient's older brother had died of idiopathic interstitial lung disease at 6 months of age, suggesting a genetic etiology of the disease. Sequence analyses of SP- C and ABCA3 genes were performed using DNA samples from the patient himself, his parents, and his brother. These analyses revealed novel compound heterozygous mutations in the coding exons of ABCA3 in both the patient and his brother: c.2741A > G, of paternal origin, and c.3715_3716insGGGGGG, of maternal origin. Conclusion Since ABCA3 mutations seem to be a heterogeneous entity with various phenotypes, we recommend genetic testing for mutations in SP- C and ABCA3 genes to be considered in children with unexplained interstitial lung disease. [ABSTRACT FROM AUTHOR]

Recessive gene mutations in ABCA3 cause lethal neonatal respiratory distress, and pediatric and adult interstitial lung disease. The effectiveness of medical treatments is limited and a subset of such patients will eventually require lung transplantation. A 20 months old boy developed interstitial lung disease and was treated with hydroxychloroquine, which had a significant effect. Sequence analysis of ABCA3 gene revealed newly discovered compound heterozygous mutations. His respiratory dysfunction gradually progressed over years and he underwent living-donor lobar lung transplantation (LDLLT) at 8 years of age with his parents serving as bilateral lobar donors. The parents had been genetically examined beforehand and found to be carriers who had one allele with an ABCA3 gene mutation and the other with no mutation. The recipient has been well without chronic lung allograft dysfunction and his parents have been enjoying healthy social lives for 7 years since the operations. LDLLT appears to be a valid option for selected children with ABCA3 gene mutations who are too ill to wait for cadaveric lung transplantation. When relatives of the recipient with ABCA3 gene mutation are deemed potential donors for LDLLT, sequence analyses of the donors are indispensable to exclude the possibility that they are late-onset patients of this recessive hereditary disease. [ABSTRACT FROM AUTHOR]