Over the past 10 to 15 years, our knowledge of TSC and its treatment have grown considerably. Epilepsy is the most common neurologic manifestation of TSC, affecting approximately 90% of patients, and the onset of epilepsy in the majority of individuals with TSC occurs before the age of 2 years, which is a critical time in neurodevelopment. Studies have shown that seizures are a significant variable in other comorbidities of TSC, including cognitive impairment, autism, and other neuropsychiatric disorders. The TSC medical and patient communities feel very strongly that the earlier we can identify patients as having TSC, the greater the impact we can have on their lives and futures, potentially minimizing many aspects of the disorder.

We have studied missed opportunities for diagnosis, and, historically, these have included young children with seizures who presented before the widespread availability of magnetic resonance imaging, at a time when there was not as much knowledge about TSC, and so the diagnosis was not made. Although the early diagnosis of TSC has improved, we still see patients today in our clinic who have lived for decades with TSC without knowing it and without it being diagnosed until something potentially catastrophic occurs. This may arise even in someone who did not have the significant onset of seizures in childhood. For example, a previously undiagnosed adult might have the onset of severe lower back pain from a renal angiomyolipoma rupture, and hemorrhage due to such a rupture may be serious and life threatening. Therefore, knowing that a patient has TSC allows us to help make sure that they stay healthy by monitoring kidney, lung, and other possible organ involvement.

Important considerations in making early diagnoses include having an index of suspicion based on a patient's family history of TSC. In addition, some of the earliest diagnoses of TSC may occur as a result of the detection of cardiac rhabdomyomas, which may be identified during a late-gestation fetal ultrasound. If TSC is suspected, prenatal brain magnetic resonance imaging to look for tubers and genetic testing can be performed. 

Genetic testing has had a huge impact on the diagnosis of TSC. There is a program in pediatric epilepsy called Behind the Seizure that facilitates free genetic testing for any child who is under 8 years old who has experienced an unprovoked seizure. This program, in particular, has had a significant effect on the early diagnosis of TSC and other rare disorders.