[Whole exome sequencing and analysis of a Chinese family with familial pulmonary sarcoidosis].

Objective: To analyze the clinical features and the results of the whole exome sequencing (WES) of a Chinese family containing both pulmonary sarcoidosis patients and healthy members, and to find potent genes and variants that may be involved in the pathogenesis of sarcoidosis. Methods: Three patients with pulmonary sarcoidosis and 1 healthy member was included from a Chinese Han family in the north of China diagnosed in November 2016, which characterized as 2 consecutive generations including 2 males and 1 female, aged from 23 to 69 years old. The proband is Ⅱ-6. Pulmonary sarcoidosis was diagnosed by clinical features, imaging and pathological findings, and clinical data such as family history were collected. Whole blood samples were taken and WES (Illumina NovaSeq S2) was performed. The pathogenicity analysis and gene annotation analysis were performed by ExAC, SIFT, Polyphenv2, Metascape databases. Results: It was found that 27 genes were highly pathogenic in the database filtering result. After gene annotation analysis, we found that ZC3H12A gene can negatively regulate the differentiation of Th17 cells, which may be involved in the onset of pulmonary sarcoidosis. Sanger sequencing confirmed the c.1361 A>G variant in 3 sarcoidosis patients but normal in healthy member. Conclusions: In patients with familial pulmonary sarcoidosis, the genetic background could regulate immune response which is one of the pathogenic mechanisms of sarcoidosis. The whole exome test and gene ontology analysis showed that Ⅱ-2, Ⅱ-6 and Ⅲ-1 pulmonary sarcoidosis patients in this family were all shared the same variant on ZC3H12A gene, which played a pivotal role in differentiation of Th17 cells and is a potent pathogenesis gene in this Chinese pulmonary sarcoidosis family.