Lujan syndrome is a condition characterized by intellectual disability, behavioral problems, and certain physical features. It occurs almost exclusively in males.

Lujan syndrome is caused by at least one mutation in the MED12 gene. This gene provides instructions for making a protein that helps regulate gene activity; it is involved in many aspects of early development. The MED12 gene mutation that causes Lujan syndrome changes a single protein building block (amino acid) in the MED12 protein. This genetic change alters the structure, and presumably the function, of the MED12 protein. However, it is unclear how the mutation affects development and leads to the cognitive and physical features of Lujan syndrome.

Lujan syndrome appears to be an uncommon condition, but its prevalence is unknown.

This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

Published Date: December 01, 2012
Published By: National Institutes of Health