**Core Concept:** Tuberous sclerosis is a genetic disorder characterized by benign tumors in various organs, most commonly the brain, kidneys, and heart. It is caused by mutations in one of three genes: TSC1, TSC2, or a rare autosomal recessive inheritance pattern.

**Why the Correct Answer is Right:** Tuberous sclerosis is caused by mutations in either TSC1 or TSC2 genes, which leads to the impairment of the tuberous sclerosis complex (TSC) protein function responsible for inhibiting the mTOR (mammalian target of rapamycin) pathway. This results in uncontrolled cell growth and formation of benign tumors in various organs.

**Why Each Wrong Option is Incorrect:**

A. Autosomal dominant inheritance pattern (Tuberous sclerosis is autosomal dominant; however, the correct answer is autosomal recessive, as explained above)
B. X-linked inheritance pattern (Tuberous sclerosis is not X-linked)
C. Mitochondrial inheritance pattern (Tuberous sclerosis is not related to mitochondrial genetics)
D. Inherited through the Y chromosome (Tuberous sclerosis is not Y-linked)

**Clinical Pearl:** Understanding genetic inheritance patterns is crucial for diagnosing and counseling patients with genetic disorders like tuberous sclerosis, which can be inherited through different modes of inheritance based on the specific gene involved (e.g., autosomal dominant, autosomal recessive, X-linked, etc.).

**Correct Answer:** **Autosomal Recessive Inheritance**

Tuberous sclerosis is caused by mutations in the TSC1 or TSC2 genes, leading to an autosomal recessive inheritance pattern. In this mode of inheritance, an affected individual requires two mutated alleles (one from each parent) to develop the disease. If both parents carry the mutated gene but have normal phenotype (heterozygous), their children have a 25% chance of being affected, a 50% chance of being carriers, and a 25% chance of being unaffected.