In Klippel-Feil syndrome, the patient has all of the following clinical features, EXCEPT:
**Core Concept**
Klippel-Feil syndrome is a rare congenital disorder characterized by the abnormal fusion of any two of the seven cervical vertebrae, leading to various clinical manifestations. This condition is often associated with other anomalies, including skeletal, muscular, and neurological abnormalities.
**Why the Correct Answer is Right**
The clinical features of Klippel-Feil syndrome include limited neck movement, low posterior hairline, and a variety of neurological symptoms such as spasticity, muscle weakness, and sensory deficits. The fusion of cervical vertebrae can lead to spinal cord compression, resulting in neurological impairment. The condition is often associated with other anomalies, such as scoliosis, heart defects, and developmental delays.
**Why Each Wrong Option is Incorrect**
* **Option A:** Limited neck movement is a common feature of Klippel-Feil syndrome due to the fusion of cervical vertebrae. This option is incorrect because it is a characteristic of the condition.
* **Option C:** Low posterior hairline is a frequent finding in patients with Klippel-Feil syndrome due to the abnormal development of the cervical spine. This option is incorrect because it is a typical feature of the condition.
* **Option D:** Spasticity and muscle weakness are common neurological symptoms associated with Klippel-Feil syndrome due to spinal cord compression. This option is incorrect because it is a characteristic of the condition.
**Clinical Pearl / High-Yield Fact**
Klippel-Feil syndrome often presents with a characteristic "turtle neck" appearance due to the limited neck movement and low posterior hairline. This clinical feature is a key diagnostic clue for the condition.
**Correct Answer: A.**