How do people inherit alpha thalassemia X-linked mental retardation syndrome?
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 mental retardation. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.