Gene mutations in sporadic lymphangioleiomyomatosis and genotype–phenotype correlation analysis

Abstract

Background Sporadic lymphangioleiomyomatosis (S-LAM) is a rare neoplasm with heterogeneous clinical features that is conventionally considered to be related to TSC2 . This study serves to elucidate the mutation landscape and potential correlation between S-LAM genomic profiles and clinical phenotypes. Methods Genomic profiles of 22 S-LAM patients were obtained by sequencing genomic DNA and cell-free DNA from various specimens using an NGS (next-generation sequencing)-based tumor-driver gene panel. Detected mutations were summarized. Symptoms, serum vascular endothelial growth factor D (VEGF-D) values, pulmonary function, and six-minute walk distance (6MWD) were compared among groups with different TSC2 status and genotypes to analyze genotype–phenotype correlations. Results 67 Variants in 43 genes were detected, with a TSC2 mutation detection rate of 68.2%. The TSC2 detection rate was similar in specimens obtained either through transbronchial lung biopsy (TBLB) or surgical lung biopsy (70.0% vs. 69.2%, p > 0.05). A novel mutation in VEZF1 (c.A659G) was detected in four participants and may represent a mild disease state. TSC2 mutation was significantly related to a shorter 6MWD ( p < 0.05), and a higher percentage of VEGF-D over 800 pg/mL ( p < 0.05); stop-gain mutation was significantly related to a higher prevalence of pneumothorax. Conclusions Tumor-driver mutations in genes other than TSC2 may have a role in S-LAM, and TBLB specimens are practical alternatives for genomic analysis. TSC2 mutation detectability and types are related to the disease severity and phenotypes of S-LAM. Supplementary Information The online version contains supplementary material available at 10.1186/s12890-022-02154-0.

The Epidemiology and Clinical Features of Lymphangioleiomyomatosis (LAM): A Descriptive Study of 33 Case Reports

“…The protein products of TSC1 and TSC2, hamartin, and tuberin, respectively, form a complex that inhibits the activity of the protein mTOR, regulating cellular proliferation. In LAM, the deletion of hamartin or tuberin results in constitutive activation of mTOR and cellular proliferation [ 7 ].…”