Genotype-phenotype correlation of patients with tuberous sclerosis complex–associated renal angiomyolipoma: a descriptive study

Abstract

TSC2 gene mutation was repeatedly reported to be associated with a more severe phenotype in patients with tuberous sclerosis complex (TSC). Our current study aims to further explore whether there is such a correlation in patients with TSC-associated renal angiomyolipoma (TSC-RAML). TSC1/TSC2 gene mutation was screened by high-throughput sequencing in 25 TSC-RAML patients from 2 medical centers. Clinical data were also carefully collected. Linear regression analysis and Student t-test were conducted by IBM SPSS Statistics Version 21.0 to analyze the genotypic-phenotypic relationship. The results indicated a high level of TSC gene mutation (80%; 20/25) in TSC-RAML patients, with higher frequency of TSC2 mutation (68%; 17/25) than TSC1 mutation (12%; 3/25). Seven novel mutation sites were detected in this study. In general, there were no significant correlations between tumor size and age (r = 0.134, P = .522), hemoglobin (r = 0.255, P = .219), and serum creatinine (r = 0.043, P = .839). Patients with larger tumor size have higher risk of bleeding. Specially, it was higher hemoglobin level in patients with TSC1 mutation than ones with TSC2 mutation and without TSC mutation (P < .05). However, no difference was found in either tumor size or serum creatinine by TSC mutation genes (P > .05). Furthermore, no difference was found in tumor size, hemoglobin, and serum creatinine by TSC mutation types (P > .05). In conclusion, TSC-RAML is TSC2 mutation dominant, with the individual differences varying greatly. No definite genotype-phenotype correlation exists in patients with TSC-RAML, and it needs to be further explored.