Compound heterozygous deletions of the WWOX gene caused a WOREE syndrome associated with severe epileptic encephalopathy

Abstract Recent studies showed that germline, bi-allelic and pathogenic variants of the WWOX gene have been associated with spinocerebellar ataxia type 12 (SCAR12) and a severe WWOX-related epileptic encephalopathy (WOREE syndrome). The underlying mechanisms of the diseases are poorly understood. Here, we reported the case of a WOREE syndrome patient with early-onset refractory seizures and global neurodevelopmental delay who died at the age of two and a half years. The whole exon sequencing showed homozygous exon 6 deletions in the WWOX gene. Quantitative real-time polymerase chain reaction (PCR) confirmed that deletions were inherited from each parent. An exons 6–8 deletion was inherited from the mother, while an exon 6 deletion plus a microdeletion involving intron 5 was inherited from the father. Due to the structure of the WWOX locus encompassing the FRA16D fragile site, we confirmed the exact breakpoints using whole genomic sequencing combined with long-range PCR. Our findings extend the mutation spectrum of the WOREE syndrome and support an important role for the WWOX gene in neural development.