Analysis of renal lesions in Chinese tuberous sclerosis complex patients with different conditions of TSC1/2 genetic mutations

Objective The renal manifestations of tuberous sclerosis complex (TSC) are complicated and various. We’d like to report the information of genetic mutations in TSC patients with renal lesions, and to discuss the relationship between features of renal lesions and genetic mutations, including mutant genes and mutant types. Methods TSC patients with renal lesions who came to Urology Department of our hospital from January 1st, 2015 to January 1st, 2020 were retrospectively analyzed. TSC patients who received next generation sequencing (NGS) of TSC1/2 and imaging examinations were screened out. When familial TSC patients were confirmed, only the probands were included. The patients who had imaging evaluation in our hospital before any treatment for TSC renal angiomyolipomas (AMLs) were also selected for further analysis of relationship between genetic mutations and AML sizes. Results 70 clinically or genetically diagnosed TSC patients with renal lesions were included. The average age was 29.3±8.3 years old. Male-female ratio was 1:1.5. 15 patients (21.4%) were probands of TSC families (3 TSC1 , 10 TSC2 , and 2 NMI). 67 patients (95.8%) had bilateral renal AMLs with one patient had a pathological diagnosis of epithelioid AML ( TSC2 mutation). One patient had multiple renal cysts ( TSC2 mutation), one had renal cell carcinomas (RCCs) ( TSC1 mutation) and one had Wilms tumors ( TSC1 mutation). Among the 70 included patients, 4 patients had TSC1 mutations, 51 had TSC2 mutations, and 15 had no mutation identified (NMI). There was no statistically significant difference between TSC2 mutations and NMI groups (11.4±5.7 vs. 8.0±5.6cm, P = 0.077) when considering AML sizes. There was also no statistically significant difference among AML sizes of patients with TSC2 mutation types of nonsense, missense, frameshift, slipping, and fragment deletion ( P = 0.712). And no statistically significant difference was found between maximus diameters in familial and sporadic patients, either (11.4±5.8 vs. 10.5±5.8, P = 0.663). Conclusions The conditions of TSC genetic mutations will affect type and severity of renal lesions. Other focuses such as protein structure and function need to be studied for renal manifestations. Except for patients with TSC1 and TSC2 genetic mutations, patients with NMI and familial patients are also needed more attention for the pathogenesis of them is still unknown.