**Core Concept**
22q11 deletion syndrome, also known as DiGeorge syndrome, is a genetic disorder caused by a deletion of a small segment of chromosome 22. This deletion affects the development of multiple body systems, including the heart, immune system, and facial structures.

**Why the Correct Answer is Right**
The correct answer is related to the clinical manifestations of 22q11 deletion syndrome. Individuals with this condition often present with congenital heart defects, particularly right-sided outflow tract anomalies, such as tetralogy of Fallot. This is due to the deletion of the TBX1 gene, which plays a crucial role in cardiac development. Additionally, patients with 22q11 deletion syndrome may also experience cleft palate, velopharyngeal insufficiency, and immunodeficiency due to thymic hypoplasia.

**Why Each Wrong Option is Incorrect**
**Option A:** While hypocalcemia is a common feature of 22q11 deletion syndrome, it is not the most specific or characteristic manifestation of this condition.
**Option B:** Hyperparathyroidism is actually the opposite of what is typically seen in 22q11 deletion syndrome, where parathyroid gland hypoplasia or aplasia leads to hypocalcemia.
**Option C:** Although patients with 22q11 deletion syndrome may experience learning disabilities and behavioral problems, these are not the most characteristic clinical features of this condition.

**Clinical Pearl / High-Yield Fact**
Individuals with 22q11 deletion syndrome are at increased risk of developing autoimmune disorders, such as autoimmune thyroiditis, and should be monitored accordingly.

**Correct Answer: C. Tetralogy of Fallot**