A 3-month-old child has a typical mewing cry and a congenital hea disease. The most probable chromosomal abnormality is:
## **Core Concept**
The question involves identifying a chromosomal abnormality associated with a specific cry and congenital heart disease in a child. The description points towards a condition known as **Cri-du-chat syndrome**, which is characterized by a high-pitched cry that sounds similar to a cat's meow.
## **Why the Correct Answer is Right**
Cri-du-chat syndrome is caused by a partial deletion of chromosome 5, also known as **5p deletion syndrome**. This condition is known for its distinctive clinical features, which include a high-pitched cry (mewing cry), congenital heart defects, and other physical and developmental abnormalities. The syndrome is a classic example of a chromosomal deletion syndrome, where the loss of genetic material leads to the observed phenotypic features.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not specify a chromosomal abnormality commonly associated with the described clinical features.
- **Option B:** This option is incorrect as it refers to a different chromosomal condition that does not match the clinical presentation provided.
- **Option D:** This option is incorrect because it does not correspond with the known genetic basis of Cri-du-chat syndrome or similar conditions that present with a mewing cry and congenital heart disease.
## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that Cri-du-chat syndrome is one of the few chromosomal abnormalities with a characteristic cry, making it a memorable condition for exams. The syndrome's association with congenital heart defects and developmental delays also makes it a high-yield topic for clinical correlations.
## **Correct Answer:** .