Alpha thalassemia X-linked intellectual disability syndrome is an inherited disorder that affects many parts of the body. This condition occurs almost exclusively in males.

Alpha thalassemia X-linked intellectual disability syndrome results from mutations in the ATRX gene. This gene provides instructions for making a protein that plays an essential role in normal development. Although the exact function of the ATRX protein is unknown, studies suggest that it helps regulate the activity (expression) of other genes. Among these genes are HBA1 and HBA2, which are necessary for normal hemoglobin production.

Alpha thalassemia X-linked intellectual disability syndrome appears to be a rare condition, although its exact prevalence is unknown. More than 200 affected individuals have been reported.

This condition is inherited in an X-linked recessive pattern. The ATRX gene 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), one working copy of the ATRX gene can usually compensate for the mutated copy. Therefore, females who carry a single mutated ATRX gene almost never have signs of alpha thalassemia X-linked intellectual disability syndrome.

Published Date: August 01, 2009
Published By: National Institutes of Health