Unrecognized Lung Disease in Classic Rett Syndrome A Physiologic and High-Resolution CT Imaging Study

Background: Breathing disorders in Rett Syndrome (RS) have been generally attributed to severe autonomic and/or brain stem dysfunction, and, to our knowledge, no information regarding lung morphologic characteristics exists to date. The aim of the present study was to determine if there are RS-associated pulmonary abnormalities. Methods: A total of 27 female subjects (age, M +/- SD: 12.6 +/- 5.9 y; age range: 3-32 y) with gene-encoding, methyl-CpG-binding-protein-2-mutation-confirmed RS underwent high-resolution CT (HRCT) scans of the thorax. A volumetric acquisition was used, and isotropic data sets were acquired with thin collimation (< 1-mm slice), scanning through the lungs and processing on a high-spatial-resolution kernel (bony algorithm). Results: Abnormal HRCT scan findings were observed in 15 of 27 (55.5%) cases, consisting of centrilobular nodules (10/15, 66.7%), thickening of the bronchial walls (8/15, 53.33%), and patchy ground-glass opacities (4/15, 26.7%), with upper lobe predominance. In addition, bronchiolectasis were found in nine of 15 (60%) patients. Conclusions: Pulmonary lesions, respiratory bronchiolitis-associated interstitial lung disease-like lesions, are present on imaging studies in about half of typical patients with RS. Further research is needed to clarify the epidemiologic characteristics and the pathogenesis of these previously unrecognized pulmonary abnormalities. CHEST 2010; 138(2):386-392