Identification of novel variants in BRF1 gene from patient with developmental delay, hearing abnormality, and nervous system anomalies.

Cerebellofaciodental syndrome characterized with dysmorphic features, intellectual disability, and brain anomalies. Now its clinical spectrum expanded more manifestations including bilateral sensorineural hearing impairment and inner ear malformation. Here, we report a 14-month-old boy with global developmental delay and hearing disorder. Whole exome sequencing (WES) revealed the compound heterozygous variants [NM_001519.4: c.652 T > G (p.W218G); c.915 + 1G > T] in the BRF1 gene which inherited from his parents, respectively. The MRI results showed hypoplastic cerebellar vermis, enlarged cisterna magna, and prominent fourth ventricle, the rehabilitation therapy failed to improve the symptoms for our patient. Our finding expands the genetic spectrum of BRF1 variants, which indicates patients with the developmental delay caused by BRF1 variants require other treatments instead of rehabilitation.