Incidence of Tuberous Sclerosis Complex
The incidence of tuberous sclerosis complex (TSC) at birth is approximately 1 in 5,800 live births, affecting over one million patients worldwide. 1
Epidemiological Data
The birth incidence of TSC is well-established across multiple high-quality sources:
- Primary incidence figure: 1 in 5,800 live births 1
- Alternative estimates: Research literature reports a range of 1 in 5,000 to 10,000 live births, with some sources citing 1 in 6,000 2, 3, 4, 5, 6
The slight variation in reported incidence likely reflects differences in study populations, diagnostic criteria evolution, and improved detection methods over time. The most recent 2024 guideline consensus supports the 1 in 5,800 figure as the most accurate current estimate. 1
Prevalence vs. Incidence
While the birth incidence is 1 in 5,800, the population prevalence is estimated at approximately 1 in 20,000, which accounts for mortality throughout the lifespan. 2 This discrepancy highlights that TSC carries significant morbidity and mortality risks, particularly from:
- Epilepsy complications (status epilepticus and sudden unexpected death in epilepsy) 1
- Kidney disease (the most common cause of death in adults with TSC) 1
- Infectious complications 1
Genetic Inheritance Pattern
TSC follows an autosomal dominant inheritance pattern, but the majority of cases arise de novo: 7
- De novo mutations: Two-thirds to three-fourths of all TSC cases result from new mutations 7
- Inherited cases: Only one-quarter to one-third have an affected parent 7
- Germline mosaicism risk: Parents of a child with apparently sporadic TSC have a 1-2% risk of having another affected child due to possible germline mosaicism 7
Clinical Recognition Challenges
Despite this relatively high incidence, TSC remains underrecognized in clinical practice because less than 40% of patients present with the classic triad of facial angiofibromata, developmental delay, and intractable epilepsy. 1, 7 This underscores the importance of maintaining clinical suspicion and utilizing both major and minor diagnostic criteria for identification. 7