Clinical and genetic study of 20 patients from China with Cornelia de Lange syndrome

BACKGROUND Cornelia de Lange syndrome (CdLS) is a rare congenital syndrome with no racial difference. The objective of this study is to report the clinical characteristics and genetic study of 20 CdLS cases from China. METHODS This is an observational study. Suspected patients were referred for further confirmation, clinical treatment, and genetic testing under voluntary condition. Demographic data and family history, data of clinical manifestations including facial dysmorphism and developmental delay of each patient were collected. Chromosomal analysis and NIPBL/SMC1A/SMC3 gene mutational analysis were carried out by PCR, reverse transcription PCR direct sequencing in the probands, and SNP array to detect the genome-wide copy number variations. RESULTS Twenty CdLS cases from China were included in this study. Facial dysmorphisms, feeding difficulties, and developmental delay were the major clinical manifestations. Seven patients underwent gene mutation tests. Both the SMC1A and SMC3 gene mutation tests were negative in all. A heterozygous mutation in exon 20 of the NIPBL gene in proband 2, and a heterozygous mutation in intron 38 of the NIPBL gene in proband 3 were found in 1 patient, and RT-PCR revealed a splicing mutation in exon 38, generating both normal transcript and an aberrant alternatively spliced transcript with exon 38 deletion. CONCLUSIONS Clinical manifestations of CdLS patients from China are similar to those in the other countries. Heterozygous mutations of NIPBL gene were found.