Identification of a novel missense NIPBL variant in a juvenile with severe type of Cornelia de Lange syndrome / 中华医学遗传学杂志

ABSTRACT

OBJECTIVE@#To detect pathogenic variant in a juvenile with severe type Cornelia de Lange syndrome (CdLS).@*METHODS@#A 12-year-old female presented with comprehensive developmental retardation and deformity of lower limbs. Genomic DNA was extracted from peripheral blood sample of the patient. Whole exome sequencing was performed to identify pathogenic variants. Putative variant was verified by Sanger sequencing. The impact of variants was predicted and validated by bioinformatic analysis.@*RESULTS@#A de novo missense variant, c.1507A>G (p. Lys503Glu), was found in the NIPBL gene of the proband. The variant was unreported previously and predicted to be pathogenic by PolyPhen-2, MutationTaster and SIFT. Using HomoloGene system, the 503 loci in the NIPBL protein are highly conserved. The change of amino acid (Glu), locating in 503 locus, was found to cause the Neuromodulin_N superfamily domain destroyed, resulting in severe damage to the function of NIPBL protein.@*CONCLUSION@#The de novo missense variant c.1507A>G (p. Lys503Glu) of the NIPBL gene probably underlies the disease in this patient.