Val667Ile is a de novo variant discovered in the GRIN2D gene found to be associated with Developmental and Epileptic Encephalopathies (DEEs). DEEs are a group of devastating disorders that involve global developmental delay and epileptic abnormalities. Patients with this variant exhibit a range of cognitive and motoric impairments, including intractable epilepsy, intellectual disabilities, motor deficits and premature death. The market lacks suitable treatments that alleviate these symptoms, and available therapy is focused solely on the epileptic phenotype. Our aim is to find a therapy that targets the developmental phenotype in addition to the epileptic. A cholesterol 24-hydroxylase inhibitor has been found to reduce seizures and prolong life expectancy in Dravet syndrome mice. We tested this compound on a Grin2d Val667Ile mouse model, an inducible, cre/loxP-based mutant that mimics the human phenotype The mice exhibit motor and cognitive impairments, epileptic brain activity and premature death. We treated the mice with this inhibitor in two different age groups and performed various behavioral assays such as rotarod, open field, and Y-maze, performed EEG analysis and measured survival. Our studies found that mice that received this compound had an increased life span and exhibited improved motor coordination and balance when compared to mice that received the control. We believe that cholesterol 24-hydroxylase inhibitor exhibits therapeutic potential as a treatment for patients suffering from GRIN2D-related co-morbidities. We are continuing to perform various experiments that will allow us to understand the mechanism underlying these therapeutic abilities and to characterize the specific effects of this drug.