Cyclin D is a key regulator of the cell cycle, and its dysregulation can lead to abnormal cell proliferation.13 Centrosomal proteins such as NIN and CEP170 influence mitotic progression, and it is plausible that the p.Glu1136del variant perturbs cell cycle dynamics, particularly during the early development of neural progenitor cells.14 This disruption could manifest as microcephaly and growth failure, which are prominent features of the patient’s condition. This evidence concerns the gene CEP170 and microcephaly.