MED13L gene

mediator complex subunit 13 like

The MED13L gene provides instructions for making a protein that is one piece (subunit) of a group of proteins known as the mediator complex. This complex regulates the activity (transcription) of genes. Transcription is the first step in the process by which information stored in a gene's DNA is used to build proteins.

The mediator complex physically links the proteins that can turn genes on, called transcription factors, with the enzyme that carries out transcription, called RNA polymerase II. Once transcription factors are attached to RNA polymerase II, transcription begins.

Researchers believe that as part of the mediator complex, the MED13L protein is involved in many aspects of early development, including development of the heart, nerve cells (neurons) in the brain, and structures in the face. The mediator complex plays a role in several chemical signaling pathways within cells. These pathways help direct a broad range of cellular activities, such as cell growth, cell movement (migration), and the process by which cells mature to carry out specific functions (differentiation).

More than 50 mutations in the MED13L gene have been found to cause MED13L syndrome. This condition is characterized by moderate to severe developmental delay and intellectual disability and minor differences in facial features. Additionally, some people with MED13L syndrome have recurrent seizures (epilepsy) or heart abnormalities that are present from birth (congenital heart defects).

Some MED13L gene mutations insert or delete regions of DNA within the MED13L gene. These genetic changes lead to a reduction in the total amount of MED13L protein in cells. Other mutations change single protein building blocks (amino acids) in the MED13L protein. It is thought that the altered protein interferes with the function of the normal protein produced from the non-mutated copy of the MED13L gene (such mutations are described as "dominant-negative"). Because dominant negative mutations impair the function of proteins made from both the altered copy of the MED13L gene and the normal copy, individuals with dominant negative mutations tend to have more severe signs than people with mutations that affect protein production from just the altered copy of the gene. While it is likely that mutations in the MED13L gene impair the control of gene activity by the mediator complex, it is unclear how these changes lead to the particular cognitive and physical features of the disorder.

Genetics Home Reference provides information about critical congenital heart disease.

Cytogenetic Location: 12q24.21, which is the long (q) arm of chromosome 12 at position 24.21

Molecular Location: base pairs 115,958,576 to 116,277,693 on chromosome 12 (Homo sapiens Updated Annotation Release 109.20200522, GRCh38.p13) (NCBI)

Cytogenetic Location: 12q24.21, which is the long (q) arm of chromosome 12 at position 24.21
  • KIAA1025
  • PROSIT240
  • THRAP2
  • TRAP240L