Developmental epileptic encephalopathies (DEE) are a group of over 50 different conditions. The diseases are characterized by early onset, difficult to treat seizures and slowing or regression of development. The different types of DEEs can be identified based on the underlying genetic variants.
DEE 56 or epileptic encephalopathy, early infantile 56 is a relatively newly identified disorder caused by a variant in the YWHAG gene. It is caused by a new (de novo) variant in the gene that has not been inherited from either parent. The condition is autosomal dominant meaning that only one affected copy of the gene is needed for the disease to be expressed.
Common symptoms associated with DEE 56 include: early onset epilepsy, intellectual disability, motor developmental delay and speech impairment. Less common symptoms include behavioral problems, abnormal curvature of the spine (scoliosis), poor muscle control (ataxia) and certain facial characteristics (facial dysmorphism). It is important to note that the symptoms of the disease can vary greatly, with some individuals having fewer symptoms and normal development.
Only about 25 individuals with DEE 56 have been identified to date (Jan/23).
YWHAG