TINF2 Gene Mutation in a Patient with Pulmonary Fibrosis

Figure 1

(a) DNA sequence of a segment of TINF2 exon 6 demonstrates a cytosine to adenine change at position c.734 that leads to the amino acid substitution of serine to tyrosine at codon 245. M denotes that both a cytosine and an adenine nucleotide at cDNA position 734 are present, indicating a heterozygous mutation. (b) Lung biopsy specimen of our patient taken at the time of diagnosis (H&E 12,5x). The biopsy shows temporal and spatial heterogeneous fibrosis consistent with a usual interstitial pneumonia (UIP) pattern: marked subpleural fibrosis with honeycombing (F) and central sparing (★), and the presence of fibroblast foci (inset 200x, arrows). No features suggestive of an alternative diagnosis were seen. Specifically, histologically, there was no granulomatous disease or lymphocytic interstitial pneumonia pattern present suggestive of granulomatous-lymphocytic interstitial lung disease (GLILD) and there was no interstitial elastosis suggestive of pleuroparenchymal fibroelastosis (PPFE). (c) HRCT scan image of the lungs of our patient when she was referred for lung transplantation. The scan shows thickening of the inter- and intralobular septae, in both the subpleural and peribronchovascular areas. Honeycombing is seen on the left. This is inconsistent with a UIP pattern, due to the peribronchovascular extension of the fibrosis. No radiological features suggestive of alternative diagnoses were seen. Specifically, there were no pulmonary micronodules that are typical of GLILD, and there was no pleuroparenchymal thickening in the upper lung zones, which is typical of PPFE. With these findings combined, the patient can be classified as a case of possible IPF, in accordance with current guidelines [14].

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