Abstract: Objective To identify etiology of a child with early infantile-onset epileptic encephalopathy. Methods Clinical data of a child with early infantile-onset epileptic encephalopathy were collected. DNA was extracted from peripheral blood of the child and his parents. Whole exome sequencing and copy number variation were performed, and the result was confirmed by Sanger sequencing. The relevant literature of WWOX gene was reviewed. Result The patient was a three-monthold boy who was taken to hospital for repeated seizures in a month, manifested as multiple focal seizures and infantile spasms, and the phenotype of his parent is normal. Compound heterozygous mutaions of c.183C>G (p.Tyr61*) inherited from his mother and c.178-16T>G inherited from his father in WWOX gene were detected in the proband, which were classified as “likely pathogenic” and “uncertain”, respectively, according to the American Society for Genetics and Genomics Guidelines. After oral administration of levetiracetam combined with nitrazepam, the child still suffered from recurrent epilepsy, with serious mental and motor developmental retardation, and hypotonia. There were 22 articles in languages other than Chinese provided case data of more than 30 mutation loci in 64 patients, compound heterozygous and homozygous mutations were the two commonest, and the latter mostly coming from consanguineous families in the Middle East, who were mainly manifested as early infantile-onset epileptic encephalopathy. Conclusion The study identified a novel compound heterozygous mutation of WWOX gene in a child with early infantile-onset epileptic encephalopathy, providing basis for family genetic counseling; seizures caused by WWOX gene mutation are refractory to medicine administration.

Key words: WWOX gene; epilepsy; encephalopathy