Mutations in the COL18A1 gen associated with knobloch syndrome and structural brain anomalies:a novel case report and literature review of neuroimaging findings

COL18A1 gene mutations have been associated with Knobloch syndrome, which is characterized by ocular and brain abnormalities. Here we report a 4.5 years-old male child with autism and two novel COL18A1 mutations (NM_030582.4: c.1883_1891dup and c.1787C>T). Hypermetropic astigmatism, but not brain migration disorders, was observed. However, an asymmetric pattern of cerebellar perfusion and a smaller arcuate fascicle were found. Low levels of collagen XVIII were also observed in the patient’s serum. Thus, biallelic loss-of-function mutations in COL18A1 may be a new cause of autism without the brain malformations typically reported in patients with Knobloch syndrome.