Diagnosis of tuberous sclerosis complex in the fetus.

Tuberous sclerosis complex is a dominantly inherited genetic disorder of striking clinical variability. It is caused by mutations in either TSC1 or TSC2 gene, which regulate cell growth and proliferation by inhibition of mTORC1 signaling. TS is characterized by the development of benign tumors in many tissues and organs and its neurological manifestations include epilepsy, autism, cognitive and behavioral dysfunction, and giant cell tumors. With mechanism-based mTOR inhibitors therapy now available for many of its manifestations, early diagnosis of TSC is very important in order to offer appropriate care, long-term surveillance and parental counseling. Fetal ultrasound and MRI imaging techniques have evolved and may capture even earlier the following TSC-associated lesions: cardiac rhabdomyomas, subependymal nodules, cortical tubers and renal cysts. Often these represent an incidental finding during a routine ultrasound. Furthermore, in the past decades prenatal molecular diagnosis of TSC has emerged as an important option for families with a known affected member; however, the existing evidence with regards to the clinical characteristics and long-term outcome of babies diagnosed prenatally with TSC is yet limited and the path that follows early TSC detection merits further research.