## **Core Concept**
Tuberous sclerosis complex (TSC) is a genetic disorder characterized by the growth of non-cancerous tumors in various parts of the body, including the brain, eyes, kidneys, heart, lungs, and skin. It is caused by mutations in the TSC1 or TSC2 genes, leading to the mTOR pathway dysregulation. Early diagnosis and identification of TSC are crucial for managing its manifestations.

## **Why the Correct Answer is Right**
The correct answer, **Hypopigmented macules**, is often considered one of the earliest and most common dermatological manifestations of tuberous sclerosis. These macules, also known as ash-leaf spots, are usually present at birth or appear during early infancy. They are more easily visible under UV light (Wood's lamp examination) and are a key diagnostic criterion for TSC.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While **Shagreen patches** are a dermatological feature of TSC, they typically appear later in childhood, not as early as hypopigmented macules.
- **Option B:** **Angiofibromas** are also a feature of TSC but tend to appear later in childhood, often after the age of 2-3 years.
- **Option D:** **Subependymal nodules** are a type of brain lesion associated with TSC, but their identification requires imaging studies, and they are not as easily or early detected as skin manifestations like hypopigmented macules.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that hypopigmented macules (ash-leaf spots) are often one of the earliest signs of tuberous sclerosis and can be present at birth or early infancy. Using a Wood's lamp can help in identifying these lesions, making it a useful tool in the diagnostic workup for TSC.

## **Correct Answer:** . Hypopigmented macules