Rett Syndrome researchers will now have 35 genetic samples to work with to improve diagnosis of the neurodevelopmental disorder, after a new study, published in The Journal of Molecular Diagnostics, conducted by the Centers for Disease Control and Prevention (CDC). In 1999, researchers identified the gene mutation linked to Rett Syndrome, but, until now, they lacked the test material needed to conduct deeper research.

Rett Syndrome develops in approximately one out of every 10,000 births and predominantly affects girls. While the girls are born without visible symptoms, they begin to show delays in development, slower brain and head growth, and impaired motor difficulties (such as the coordinated use of their hands) between 1 and 4 years old. As the girls get older, more severe symptoms might emerge, like the inability to speak, seizures, repetitive hand movements, muscle weakness, and an abnormal posture. There is currently no cure for Rett syndrome, though occupational therapy may help regulate the physical symptoms.

The 35 samples of gene variants could help doctors diagnose Rett Syndrome earlier and more accurately. The samples were made available through a study conducted as part of the CDC Genetic Testing Reference Materials Coordination Program (GeT-RM), an organization that helps genetic testing researchers get lab material for inherited genetic disorders.

Researchers chose DNA samples from Rett Syndrome patients in the National Institute of General Medical Sciences’ Coriell Cell Repository and also acquired cell lines from the blood samples of patients with Rett Syndrome. These samples contain the most common mutations seen in Rett Syndrome, including the gene mutation first identified in 1999: the Methyl CpG Binding Protein 2 Gene (MECP2).

Scientists believe the MECP2 gene regulates brain development because it controls the release of the MeCP2 protein. The MeCP2 protein helps form and strengthen the connections between cells in the brain so they can function properly. The strength of these connections impacts how our brain sends signals to other parts of our body, thus influencing how we move and how we speak.

In a news release, Lisa Kalman from the CDC said that “the availability of a renewable source of characterized reference materials for Rett syndrome will help to ensure the accuracy of these genetic tests and facilitate research and test development.” She added that “genetic testing can help to confirm or establish the diagnosis of RS, especially when patients are young and the phenotype may not be completely apparent.” 

 

Source: Kalman L,Tarleton J, Percy A, et al. Development of a genomic DNA reference material panel for Rett Syndrome (MECP2-related disorders) genetic testing. The Journal of Molecular Diagnostics. 2014.