There is little question that familial interstitial pneumonia (FIP) is a recognized condition based on the large quantity of data supplied. FIP presented clinically in the same way as sporadic instances of idiopathic interstitial pneumonia (IIP), with the exception of the familial history, or it occurred at a younger age of start. Due to increased knowledge of the disease among family members, who may seek early screening and be recognized early, the lower age of onset might be a misrepresentation. The majority of genes revealed had some overlap between FIP and the sporadic types of IIP, suggesting that their genetics were pointing to something distinct. It was likely that patients with FIP were more severely burdened by genetic risk factors than sporadic ones. Rare variants in TERT or TERC with large deleterious effects, for example, were more penetrant and had a higher representation in FIP than in sporadic idiopathic pulmonary fibrosis (8% to 18% vs. 1% to 3%, respectively), whereas common variants with lower penetrance and small effect might be more prevalent in sporadic idiopathic pulmonary fibrosis.
Overall, genes revealed via familial research and massive genome-wide association studies validated at least three genes, TERT, TERC, and MUC5B, as essential genes in the development of pulmonary fibrosis, as well as numerous additional sites. It demonstrated that FIP and IIPs, in general, are multigenic disorders that cannot be classified as single-gene diseases. The findings, together with evidence of environmental factors, pointed to a multifaceted etiology of lung fibrosis in both FIP and sporadic IIP.