Abstract
Epileptic encephalopathies are severe seizure disorders accompanied by intellectual disability. Whole-exome sequencing technology has enabled the discovery of genetic mutations responsible for a wide range of diseases, and severe epilepsy and neurodevelopmental diseases are often associated with rare de novo mutations. We identified a novel de novo frameshift mutation in the PPP3CA gene encoding calcium-dependent protein phosphatase (calcineurin) catalytic subunit A (c.1255_1256del, p.Ser419Cysfs*31) in an 11.5-mo-old female with early-onset refractory epilepsy and developmental delay. This finding expands the list of PPP3CA mutations associated with early-onset severe neurodevelopmental disease with seizures and provides further details on clinical features.