Case report: A novel truncating variant of BCL11B associated with rare feature of craniosynostosis and global developmental delay.

Craniosynostosis is a premature fusion of cranial sutures, resulting in abnormally shaped skull and brain development disorder. The description of craniosynostosis in patients with mutations is rare. Here, we firstly report a 25-month-old Chinese boy with a novel frameshift variant in gene. The patient was identified c.2346_2361del by whole-exome sequencing and was confirmed to be by parental Sanger sequencing. This patient presented clinical phenotype of craniosynostosis as well as global developmental delay. He had a small mouth, thin upper lip, arched eyebrows, a long philtrum, midfacial hypoplasia and craniosynostosis. Brain MRI showed brain extracerebral interval and myelination changes, and brain CT with 3D reconstruction showed multi-craniosynostosis. Our study expands the clinical phenotypes of patients with gene mutation, and our findings may help guide clinical treatment and family genetic counseling.