**Question:** A 50-year-old woman who was obese and hypertensive, came with complaints of bleeding and abdomen pain, diagnosed to be endometrial cancer. Which of the following gene is mutated?

A. TP53
B. BRCA1
C. PTEN
D. KRAS

**Core Concept:** Endometrial cancer is a type of cancer that develops from the inner lining of the uterus (endometrium). This cancer is more common in obese, postmenopausal women, and is often associated with hormonal changes, such as those seen in hypertension. Mutations in certain genes can be linked to an increased risk of developing endometrial cancer.

**Why the Correct Answer is Right:** Endometrial cancer is a disease characterized by the uncontrolled growth of cells within the endometrium. Among the provided options, the correct answer is **D. KRAS**.

**Why Each Wrong Option is Incorrect:**

A. TP53 (Option A) is a tumor suppressor gene that plays a crucial role in preventing the formation of cancer by regulating cell division and preventing uncontrolled growth. Mutations in TP53 do not directly cause endometrial cancer but can be associated with other types of cancer.

B. BRCA1 (Option B) and BRCA2 are known for their roles in breast and ovarian cancer susceptibility, not endometrial cancer. Mutations in BRCA1 and BRCA2 genes increase the risk of breast and ovarian cancer, but not endometrial cancer.

C. PTEN (Option C) is a tumor suppressor gene that regulates cell growth, proliferation, and apoptosis (cell death). Mutations in PTEN are associated with an increased risk of developing certain types of cancer, including endometrial cancer. However, PTEN is not specifically linked to endometrial cancer as strongly as KRAS is.

**Clinical Pearl:** Mutations in the KRAS gene (Option D) are strongly associated with an increased risk of endometrial cancer. The KRAS gene encodes a protein that plays a role in cell growth and differentiation. Mutations in this gene can lead to uncontrolled cell growth and the development of tumors like endometrial cancer.

**Answer Explanation:**

The correct answer, KRAS (Option D), is associated with the development of endometrial cancer due to its role in cell growth and differentiation. Mutations in the KRAS gene can lead to uncontrolled cell growth and the formation of tumors like endometrial cancer.

**Why Not the Other Options:**

A. TP53, B. BRCA1, and C. PTEN are associated with different types of cancer, such as breast and ovarian cancer, but not specifically linked to endometrial cancer.

**Clinical Pearls:**

1. Mutations in the KRAS gene contribute to uncontrolled cell growth and tumor development, including endometrial cancer.
2. Understanding these associations between genes and cancer types is essential for medical professionals to make accurate diagnoses and develop appropriate treatment plans for patients.