EFNB1 gene

ephrin B1

The EFNB1 gene provides instructions for making a protein called ephrin B1. This protein spans the membrane that surrounds the cell. The portion outside the cell attaches (binds) to proteins called Eph receptor kinases on the surface of neighboring cells. Together, these proteins form Eph/ephrin complexes, which help cells stick to one another (cell adhesion) and communicate. Communication between the attached cells plays a critical role in the normal shaping (patterning) of many tissues and organs before birth. In the brain, Eph/ephrin complexes also play a part in the development of nerve cells (neurons) and in the ability of the connections between neurons (synapses) to change and adapt over time in response to experience (synaptic plasticity).

More than 115 mutations in the EFNB1 gene have been found to cause craniofrontonasal syndrome. This rare condition is characterized by the premature closure of certain bones of the skull (craniosynostosis) during development, which affects the shape of the head and face. Females with craniofrontonasal syndrome typically have more severe signs and symptoms than affected males, who often have one or two features of the condition.

Mutations in the EFNB1 gene result in a shortage (deficiency) of ephrin B1 protein. Most of these mutations lead to an abnormally short version of the molecule that acts as the genetic blueprint used to make the ephrin B1 protein. The shortened molecules are quickly broken down before protein can be produced. A deficiency of ephrin B1 protein prevents the adhesion and communication between cells that aids in proper development , which disrupts normal patterning in tissues before birth. Abnormal development of the skull and other facial structures leads to the signs and symptoms of craniofrontonasal syndrome.

Cytogenetic Location: Xq13.1, which is the long (q) arm of the X chromosome at position 13.1

Molecular Location: base pairs 68,828,997 to 68,842,164 on the X chromosome (Homo sapiens Updated Annotation Release 109.20191205, GRCh38.p13) (NCBI)

Cytogenetic Location: Xq13.1, which is the long (q) arm of the X chromosome at position 13.1
  • EFL3
  • EFNB1 gene
  • Elk-L
  • ELKL
  • EPLG2