## Core Concept
Natal teeth are teeth that are present at birth, and they can be associated with various conditions. Understanding the conditions associated with natal teeth is crucial for identifying the exception.

## Why the Correct Answer is Right
The conditions associated with natal teeth include **van der Woude syndrome**, **Pierre Robin sequence**, and **ectodermal dysplasia**. These conditions often present with multiple anomalies, including cleft lip/palate, congenital heart defects, and dental abnormalities. **Down syndrome** is not typically associated with natal teeth; instead, it presents with dental anomalies like microdontia and delayed eruption.

## Why Each Wrong Option is Incorrect
* **Option A:** Van der Woude syndrome is indeed associated with natal teeth. It is a genetic disorder characterized by cleft lip and/or cleft palate and lip pits.
* **Option B:** Pierre Robin sequence can also present with natal teeth. This condition is characterized by micrognathia, glossoptosis, and often a U-shaped cleft palate.
* **Option C:** Ectodermal dysplasia is associated with various dental anomalies, including natal teeth. This group of disorders affects the development of ectodermal tissues, including teeth.

## Clinical Pearl / High-Yield Fact
A key point to remember is that natal teeth are often seen in conditions with significant congenital anomalies. When encountering a newborn with natal teeth, it's essential to look for other signs of systemic conditions. Down syndrome, while having dental anomalies, does not commonly present with natal teeth.

## Correct Answer: D. Down syndrome.