Childhood Interstitial Lung Disease in Metabolic Disorders: Prevalence, Genotypic and Clinical Characteristics, and Management Approaches: An Analysis of the Child‐Turkey Registry

OBJECTIVE: Childhood interstitial lung disease (chILD) refers to a rare and heterogeneous group of disorders that can arise from genetic or acquired causes. Interstitial lung involvement due to metabolic diseases is a rare but significant condition among chILD cases. METHODS: This retrospective descriptive study analyzed data from the chILD-Turkey registry, established in November 2021, including patients registered until August 2024. RESULTS: A total of 28 patients (3.9% of 706 children in the registry) were included, with lysosomal storage diseases (LSDs) accounting for 25 cases (89.3%) and Niemann-Pick disease (NP) being the most common diagnosis (n = 16, 57.1%), followed by Gaucher disease (GD) (n = 7, 25.0%). The mortality rate during the 3-year follow-up was 10.7% (3/28). Computed tomography (CT) most commonly revealed interlobular septal thickening (n = 17, 60.7%). No statistically significant differences in CT findings were observed between symptomatic and asymptomatic patients at the time of diagnosis. The most frequent variant in NP was c.416 T > C in SMPD1 (n = 4, 25%), and in GD, c.1448 T > C was identified in four patients (57.1%). Eight patients (2 NP and 6 GD) received enzyme replacement therapy (ERT). No increase in respiratory support needs was observed under ERT, and one patient showed significant regression in CT findings during follow-up. CONCLUSION: chILD in metabolic disorders often progresses insidiously, resulting in delayed diagnosis. While management is mostly supportive, early ERT may improve or stabilize lung disease in selected cases. Further prospective studies are needed to clarify the impact of ERT and substrate reduction therapy (SRT) on long-term pulmonary outcomes.