## **Core Concept**
Tuberous sclerosis, also known as tuberous sclerosis complex (TSC), is a genetic disorder characterized by the growth of numerous non-cancerous (benign) tumors in many parts of the body. These growths can occur in the skin, brain, kidneys, and other organs. The condition is caused by mutations in either the **TSC1** or **TSC2** genes, which are tumor suppressor genes.

## **Why the Correct Answer is Right**
The correct answer, **Autosomal Dominant**, is right because tuberous sclerosis complex is inherited in an autosomal dominant pattern. This means that a mutation in one of the two copies of the gene (either **TSC1** or **TSC2**) is sufficient to cause the condition. Individuals with the mutation have a 50% chance of passing the mutated gene to each offspring. The autosomal dominant inheritance pattern explains why the condition can affect individuals in every generation of a family, although some individuals may have a milder form of the condition or exhibit fewer symptoms.

## **Why Each Wrong Option is Incorrect**
- **Option A: X-linked Recessive** - This is incorrect because tuberous sclerosis does not display a gender bias in its inheritance pattern, nor is it linked to the X chromosome. X-linked recessive conditions predominantly affect males.
- **Option B: Autosomal Recessive** - This is incorrect because autosomal recessive conditions require mutations in both copies of the gene (one from each parent) to manifest the condition. Tuberous sclerosis, however, only requires one mutated copy of the gene.
- **Option D: Mitochondrial** - This is incorrect because mitochondrial inheritance involves conditions caused by mutations in the mitochondrial DNA. Tuberous sclerosis is caused by mutations in nuclear DNA genes (**TSC1** and **TSC2**), not mitochondrial DNA.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl for tuberous sclerosis is the presence of **adenoma sebaceum** (facial angiofibromas), which are small, benign tumors on the face, often appearing in a butterfly distribution across the cheeks and nose. This dermatological manifestation is highly suggestive of tuberous sclerosis and can aid in diagnosis.

## **Correct Answer: C. Autosomal Dominant**