Clinical symptoms of tuberous sclerosis complex in patients with an identical TSC2 mutation

Abstract

Background: Tuberous sclerosis complex (TSC) is an autosomal, dominantly inherited neurocutaneous syndrome characterized by a wide range of neurological abnormalities, tumors of different organs, and variable clinical symtomatology and severity. TSC is caused by mutations in either of two tumor suppressor genes: TSC1 or TSC2. The aim of this study was to analyze the clinical picture of TSC in patients with an identical TSC2 mutation. We tried to discover to what extent we may expect variability in the clinical set of symptoms in patients with identical mutation of TSC2 gene.

Material/methods: Mutations were identified in 100 of 170 cases. There were only 4 patients with the same type of TSC2 mutation: 5238-5255 del 18bp, del 1746 HIKRLR. Their ages were 1.5, 9, 9, and 10 years. A standardized clinical assessment of TSC symptoms was used.

Results: Epilepsy, depigmented spots, and periventricular calcification and cortical tubers were diagnosed in all the 4 patients, cardiac rhabdomyoma and angiomyolipoma of the kidneys in 3, and mental retardation and forehead fibroma in 2. Other symptoms occurred rarely or were absent. There was variability in TSC symptoms in patients with the identical type of TSC2 mutation. The main symptoms were present in all or in the majority of patients. Clinical picture also differed with the age of patient.

Conclusions: There are many influencing factors contributing to the diversity of the clinical picture and pathology of TSC. Obviously, a greater number of cases are needed for further analysis and more precise conclusions.