A novel DOCK7 variant as a rare reason for epileptic encephalopathy, cortical blindness, dysmorphic features: A case report and brief review of the literature

Abstract

Early infantile epileptic encephalopathy 23 (EIEE23; OMIM #615859) is a rare autosomal recessive disorder. It is characterized by refractory seizures, multifocal epileptic activity on electroencephalography, psychomotor development delay, dysmorphic facial features and cortical blindness/visual impairment. DOCK7 is involved in intracellular signaling networks and plays a role in axon formation and neuronal polarization. Function loss of this gene has previously been described in the molecular etiology of EIEE23. Here, we report a boy with a pathogenic novel variant in the DOCK7 gene presenting with, infantile-onset epileptic encephalopathy, severe neurodevelopmental delay, dysmorphic facial features, cortical blindness as well as previously unreported minor dental and extremity anomalies. Few cases with DOCK7 mutations have been reported in the literature. Due to its high genetic heterogeneity and scarcity, it is extremely important to report a novel and specific mutations and their associated clinical phenotypes. Whole exome sequencing revealed a novel pathogenic homozygous frameshift variant which has not been reported (c.5669dup (p.Cys1891ValfsTer2) mutation in the exon 44 of DOCK7).