To effectively treat a disease or disorder, doctors must first know the root cause. Such is the case for developmental and epileptic encephalopathies (DEEs), whose root causes can be hugely complex and heterogeneous. Scientists at St.

Jude Children's Research Hospital demonstrated the value of DNA methylation patterns for identifying the root cause of DEEs, showing specific gene methylation and genome-wide methylation "episignatures" can help identify the genes that cause DEE. The findings were published in Nature Communications . DEEs affect 1 in 590 children and involve more than 825 genes.

Current testing methods can clinically identify the root cause, or etiology, of approximately 50% of individuals' DEEs, which guides clinicians and families to appropriate care and support. However, the remaining half of all patients remain unsolved. About half of the patients with DEE will get a diagnosis, and half of them won't.

" Heather Mefford, MD, PhD, Study Co-Corresponding Author and Member, Department of Cell & Molecular Biology, St. Jude Children's Research Hospital When a child is diagnosed with DEE, linking the encephalopathy to a specific gene can allow the clinician to provide appropriate treatment or control over the symptoms of the disorder. This knowledge is also invaluable to the family.

"The half who do not receive diagnosis not only won't be able to get gene-specific recommendations in their therapy, they won't be able to link with family organizations that can connect.