Which genetic mutation is most relevant for Simpson-Golabi-Behmel syndrome?

Simpson-Golabi-Behmel syndrome is most commonly associated with mutations in the GPC3 gene. This gene encodes a heparan sulfate proteoglycan that plays a critical role in cell signaling processes, which can contribute to growth regulation during development. Mutations in GPC3 lead to disruptions in these critical pathways, ultimately resulting in the phenotypes observed in Simpson-Golabi-Behmel syndrome, including overgrowth, distinct facial features, and other associated health issues.

The other genes listed are not primarily associated with Simpson-Golabi-Behmel syndrome. For instance, CREBBP mutations are linked to Rubinstein-Taybi syndrome, GNAS mutations are associated with conditions like McCune-Albright syndrome, and MECP2 mutations are well-known for causing Rett syndrome. Understanding the specific gene involved in a condition helps in both diagnosis and management, providing insights into the underlying biological mechanisms that drive the syndrome's clinical features.