## **Core Concept**
Edwards' syndrome, also known as Trisomy 18, is a genetic disorder caused by an extra copy of chromosome 18. This condition leads to severe developmental delays, intellectual disability, and life-threatening medical problems. Key features often include growth restriction, microcephaly, overlapping fingers, and rocker-bottom feet.

## **Why the Correct Answer is Right**
The correct answer can be deduced by knowing the common characteristics of Edwards' syndrome. These typically include:
- Severe growth restriction
- Microcephaly (small head)
- Prominent occiput
- Microphthalmia and corneal abnormalities
- Low-set and malformed ears
- Overlapping index finger
- Rocker-bottom feet
- Severe intellectual disability

## **Why Each Wrong Option is Incorrect**
To accurately determine why each wrong option is incorrect, the specific features listed in options A, B, C, and D need to be provided. However, based on common features of Edwards' syndrome:

- **Option A:** If a feature commonly associated with Edwards' syndrome is listed here, it would be incorrect because it *is* a feature.
- **Option B:** Similarly, if another common feature is listed, it would be wrong for the same reason.
- **Option C:** Unless specified, assuming it's a feature, it would be incorrect.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that Edwards' syndrome has a very poor prognosis, with most children not surviving beyond early childhood due to severe medical complications. It is crucial to distinguish it from other trisomies like Down syndrome (Trisomy 21) and Patau syndrome (Trisomy 13), as each has distinct clinical features and prognoses.

## **Correct Answer: D.**