Most common cause of craniosynostosis is?
**Core Concept**
Craniosynostosis refers to the premature fusion of one or more cranial sutures, leading to abnormal skull shape and potential intracranial pressure. This condition can result from genetic, environmental, or hormonal factors affecting skull growth and development.
**Why the Correct Answer is Right**
The most common cause of craniosynostosis is genetic, specifically mutations in genes involved in fibroblast growth factor receptor (FGFR) signaling pathways. These pathways regulate osteoblast differentiation and bone growth. Mutations in FGFR1, FGFR2, FGFR3, and other genes can lead to premature suture closure and craniosynostosis.
**Why Each Wrong Option is Incorrect**
**Option A:** Environmental factors like mechanical stress or radiation can cause craniosynostosis, but they are not the most common cause.
**Option B:** Hormonal imbalances can contribute to craniosynostosis, but they are not the primary etiology.
**Option C:** Infections or inflammatory conditions can lead to cranial deformities, but they are not the most common cause of craniosynostosis.
**Clinical Pearl / High-Yield Fact**
Genetic testing for FGFR mutations is essential in diagnosing and managing craniosynostosis, especially in patients with a family history or complex craniofacial anomalies.
**Correct Answer: A. Genetic mutations in FGFR signaling pathways.**