**Core Concept**
Cleft lip and palate are congenital anomalies resulting from the abnormal development of the facial structures during embryogenesis. The etiology is multifactorial, involving genetic, environmental, and teratogenic factors.

**Why the Correct Answer is Right**
The occurrence of cleft lip and palate is associated with mutations in several genes, including IRF6, MSX1, and TGFA. The IRF6 gene plays a crucial role in the development of the facial structures, and mutations in this gene are strongly associated with cleft lip and palate. The MSX1 gene is involved in the formation of the upper jaw and lip, and mutations in this gene can also lead to cleft lip and palate.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify a gene associated with cleft lip and palate.
* **Option B:** This option is incorrect because it is not a known gene associated with cleft lip and palate.
* **Option D:** This option is incorrect because it is not a specific gene, and the mention of "other genes" is too vague.

**Clinical Pearl / High-Yield Fact**
Cleft lip and palate are among the most common congenital anomalies, and their occurrence is often associated with a family history of similar anomalies. A thorough understanding of the genetic factors involved is essential for genetic counseling and management of affected individuals.

**Correct Answer: C. IRF6, MSX1, and TGFA**