Whole‐exome sequencing identified microcephaly‐associated mutations in the NARS1 gene in more than 5000 patients with neurodevelopmental disorders, and patient‐derived induced pluripotent stem cells were used to establish cortical brain organoids with mutations of the NARS1 gene, which had small‐sized radial glial cells with reduced proliferation and cell cycle defects.104. The gene discussed is NARS1; the disease is microcephaly.