The brain MRI is normal and EEG showed hypsarrhythmia.<h4>Result</h4>The diagnosis was achieved via whole-genome sequencing which showed homozygous mutation in SYNJ1 (c.709C>T, p.Gln237*).<h4>Conclusion</h4>A clinical pattern of neonatal-onset intractable seizure, profound developmental delay, muscular hypotonia, hypsarrhythmia, and no focal abnormality of brain MRI should prompt initiation of molecular genetic analysis of SYNJ1. The gene discussed is SYNJ1; the disease is Global developmental delay.