Objective: To explore the molecular basisfor a child featuring short stature, abnormal facial features and developmental delay.
Methods: Genomic DNA was extracted from peripheral blood samples from the child and his family members. Next-generation sequencing was carried out to screen the whole exomes of the core family. Detected variants were filtered and analyzed according to the standards and guidelines for the interpretation of sequence variants recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.
Results: Trio-based sequencing has identified a de novo variant c.3593T>G (p.Val1198Gly) in the SMARCA2 gene in the patient. The variant was located in the Helicase C-terminal domain and was classified as pathogenic based on the guidelines.
Conclusion: The patient was diagnosed with Nicolaides-Baraitser syndrome caused by SMARCA2 gene mutation.