Case report
A 5 years and 7 months old girl was admitted to Changsha Hospital for maternal&Child Health care. The clinical features of the patient included postnatal growth retardation, early teething, rapid tooth replacement, dysplasia of dentition; wide eye spacing; generalized hirsutism; stubby fingers; a distinctive facial appearance, low muscle tension of the lower limbs and retarded intellectual development. Using whole-exome high-throughput sequencing detection technology and whole-genome copy number variation (CNV-seq) detection technology, using Berry Gene’s Verita Trekker® variant site detection system and Enliven® variant site annotation interpretation system Data is analyzed. One mutation of the gene KMT2A was detected in the sample of the subject. It is suggested that the c.2318dup mutation of gene KMT2A is a pathogenic mutation site (Fig1.A), which causes changes in the open reading frame of the gene, leading to changes in protein function; and the autosomal dominant genetic disease Wiedemann-Steiner and it was judged to be pathogenic. The clinical features consistent with the phenotype of this case are intellectual disability, wide eye distance, and abnormal teeth. Subsequently, the first-generation sequencing verification results showed that the proband had a heterozygous mutation of c.2318dup in gene KMT2A, and neither father nor mother had mutations. Genome copy number variants (CNVs) of unexplained clinical significance above 100Kb were detected in the sample of the subject: seq[hg19]dup(11(q24.3q25)chr11:g.130420000_131280000dup11 chromosome q24.3-q25 repeated 0.86Mb region (Fig1.B). After querying DGV, DECIPHER, OMIM, ClinGen, UCSC, gnomAD and PubMed public database resources, no clear pathogenic information and literature reports related to the fragment were found.