Rett Syndrome Causes & Risks

Causes

The majority of cases are caused by nonhereditary mutations in the Rett syndrome gene on one X chromosome. Females have two X chromosomes. Males have one X and one Y chromosome. Males usually die from mutations in the Rett syndrome gene. This is because they lack the second normal X chromosome, which partially protects females.

In Rett syndrome, the mutated gene affects methyl cytosine binding protein 2 (called MECP2). When it is mutated, there is a deficiency of this important protein. This is an area that is still being studied.

Scientists have not discovered why the Rett syndrome gene is susceptible to mutation. They also have not found what factors lead to this genetic damage. There do appear to be some “hot spots” on the gene. These hot spots are more likely to develop mutations. Because Rett syndrome is usually nonhereditary, it does not commonly occur in multiple children within a family.

Risk Factors

There are no known risk factors for Rett syndrome, except being female. The mutation that causes the syndrome appears to be sporadic.