NIPBL gene mutations in two children with Cornelia de Lange syndrome

Abstract:

Both children (one boy and one girl) experienced disease onset in infancy and visited the hospital due to growth retardation. They had unusual facies including thick hair, arched and confluent eyebrows, long and curly eyelashes, short nose, and micrognathia. Patient 1 had congenital heart disease (atrial septal defect and pulmonary stenosis) and special dermatoglyph (a single palmar crease). Patient 2 had cleft palate and moderate-to-severe deafness. Clinical features suggested Cornelia de Lange syndrome in both children. High-throughput sequencing was used to detect the seven known pathogenic genes of Cornelia de Lange syndrome, i.e., the NIPBL, SMC1A, SMC3, HDAC8, RAD21, EP300, and ANKRD11 genes. Sanger sequencing was used to analyze and verify gene mutations. Both patients were found to have novel mutations in the NIPBL gene. One patient had a frameshift mutation in exon 45, c.7834dupA, which caused early termination of translation and produced truncated protein p.R2612fsX20. The other patient had a nonsense mutation, c.505C > T, which caused a premature stop codon and produced truncated protein Q169X. Such mutations were not found in their parents or 50 unrelated healthy individuals.