Identification of novel KMT2D mutations in two Chinese children with Kabuki syndrome: a case report and systematic literature review

Background: Kabuki syndrome (KS) is a rare pediatric congenital disorder with multiple congenital anomalies and intellectual disabilities, which is inherited in an autosomal dominant manner. Mutations in KMT2D and KDM6A have been proven to be the primary cause in most cases of KS. Case presentation: Here we report two Chinese boys with clinical features of KS referred to our hospital for clinical diagnosis. Next-generation sequencing was performed on MiSeq to analyze the genetic mutations in both patients. In both, two novel de novo mutations in KMT2D gene (c.5235delA, p.(A1746Lfs*39) and c.7048G > A, p.(Q2350*)) were detected, both of which were subsequently confirmed by the two-generation pedigree analysis based on Sanger sequencing. A systematic literature review of previously reported mutational spectrum of KMT2D was also conducted. Conclusions: Two novel de novo mutations in KMT2D gene were identified and considered to be pathogenic in both of KS patients. Our data adds information to the growing knowledge on the mutational spectrum of KS.