The commonest mode of inheritance of congenital hea disease is
**Core Concept**
The question tests the understanding of the genetic basis of congenital heart disease, specifically the modes of inheritance. Congenital heart diseases are anomalies in the structure of the heart that are present at birth, and their etiology can be multifactorial, including genetic, environmental, and chromosomal factors.
**Why the Correct Answer is Right**
The most common mode of inheritance of congenital heart disease is multifactorial, which means it involves both genetic and environmental factors. This mode of inheritance suggests that congenital heart diseases are often the result of a combination of genetic predisposition and environmental influences, rather than a single gene mutation or mendelian pattern of inheritance.
**Why Each Wrong Option is Incorrect**
**Option A:** Is incorrect because while some congenital heart diseases can be inherited in an autosomal dominant pattern, this is not the most common mode of inheritance.
**Option B:** and **Option D:** Are also incorrect as they do not represent the most common mode of inheritance for congenital heart disease.
**Clinical Pearl / High-Yield Fact**
It's crucial to recognize that the multifactorial mode of inheritance implies a significant role for genetic counseling and screening in families with a history of congenital heart disease. Understanding the mode of inheritance can help in predicting the risk for siblings and offspring.
**Correct Answer:** Correct Answer: C. Multifactorial.