Ten‐year follow‐up of Nicolaides–Baraitser syndrome with a de novo mutation and analysis of 58 gene loci of SMARCA2‐associated NCBRS

Abstract

Abstract As a clinical subtype of SWI/SNF‐related intellectual disability syndromes, Nicolaides–Baraitser syndrome (NCBRS, OMIM601358) has a unique genotype–phenotype. Due to the scarcity of the number of cases reported and the limitations of diagnosis methods, so far only more than 80 cases have been reported worldwide. In this article, a new patient with a de novo mutation was followed up for 10 years; it includes the epilepsy treatment process, the characteristics of NBCRS with seizures, typical faces, sparse hair, prominent interphalangeal joints, and intellectual disability, and we also summarized the genotype–phenotype of the 80 reported cases for comparison. Due to insufficient studies and lack of attention paid to the syndrome, it is believed that the actual number of cases should be far more than the reported number. The syndrome is phased and progressive. The genotype–phenotype correlation of the disease is related to the location of the gene locus, especially closely related to the SNF2 ATPase domain. Conclusions The understanding of NCBRS is lagging, we need to strengthen the screening process of the phenotypic disease with intellectual disability, and perfecting multiple types of diagnostic techniques will help the discovery of the disease; its clinical features are staged and are slowly progressive, and long‐term prognosis must be taken precautious with long‐term follow‐up required.

Keywords

• evolving features
• genotype
• Nicolaides–Baraitser syndrome
• SMARCA2