[Identification of a novel de novo variant of CSNK2A1 gene in a boy with Okur-Chung neurodevelopmental syndrome].

OBJECTIVE:To analyze pathogenic variant of CSNK2A1 gene in a boy with Okur-Chung neurodevelopmental syndrome (OCNS). METHODS:The 8-year-old boy presented with growth retardation, intellectual disability and spells of breath holding. With genomic DNA extracted from peripheral blood samples of the patient and his parents, whole exome sequencing was carried out. Putative pathogenic variants were verified with Sanger sequencing. The nature and impact of detected variants were predicted through bioinformatic analysis. RESULTS:A novel de novo missense variant c.149A>G (p.Tyr50Cys) of the CSNK2A1 gene was identified, which was unreported previously. The variant was predicted to be pathogenic by PolyPhen-2, Mutation Taster and SIFT software. Based on a HomoloGene system, 50 loci within the CK2alpha protein are highly conserved. The change of amino acid (Cys) at position 50 has destroyed the ATP binding loop domain, causing serious damage to its function. As predicted by a Swiss PDB viewer, the variant can significantly alter the spatial structure of CK2alpha, resulting in loss of protein function. CONCLUSION:The patient's condition may be attributed to the novel de novo missense variant c.149A>G (p.Tyr50Cys) of the CSNK2A1 gene.