We herein present a patient born at term without complications who had focal tonic and tonic-clonic seizures by the second month of life. Seizures first responded to phenobarbital. Global developmental delay and axial hypotonia were diagnosed at six months old (not sitting, smiling, or cooing). At nine months of age, a unique seizure sequence of hypermotor-tonic-spasms was noticed during a long-term video-electroencephalography (video-EEG), leading to the clinical suspicion of CDKL5 deficiency disorder (CDD) based on a previous report . Her interictal EEG did not show interictal discharges, however, the background was slow (3-4 Hz delta) with a consistent posterior-to-anterior gradient of high amplitude (300-400 μV). Due to the high cost of a genetic epilepsy panel during the time of diagnosis (2011), CDKL5 gene sequencing was ordered, revealing a de novo donor splice site mutation in intron 3, c.99+1G>A. This confirmed a pathogenic variant based on a previous report and ACMG classification criteria [2, 3]. CDD is considered a developmental and epileptic encephalopathy, type 2 (OMIM # 300672). CDD presents with a full seizure sequence in 24% of cases, however, a combination of phases (predominantly tonic-spasms) is seen in 57% of patients . Therefore, encountering this sequence could facilitate the care and early counselling of these families when genetic testing is costly or difficult to obtain.