Genetic analysis of a child with ‑associated syndrome and literature study.

The present study aimed to investigate clinical phenotype and genotype characteristics of a male child with -associated syndrome (SAS) and analyzed the relationship between these characteristics and the possible underlying genetic mechanism. His clinical phenotype was analyzed. Using a high-throughput sequencing platform, his DNA samples were subjected to medical exome sequencing, screened for suspected variant loci and analyzed for chromosomal copy number variations. The suspected pathogenic loci were verified by Sanger sequencing. He presented with phenotypic anomalies of delayed growth, delayed speech and mental development, facial dysmorphism showing the typical manifestation of SAS and motor retardation symptoms. Gene sequencing result analyses revealed a heterozygous repeat insertion shift mutation in the gene (NM_015265.3) c.771dupT (p.Met258Tyrfs*46), resulting in a frameshift mutation from methionine to tyrosine at the amino acid site 258 and a truncated protein with 46 amino acids missing. The parents showed no mutation at this locus. This mutation was identified as the nosogenesis of this syndrome in children. To the best of the authors' knowledge, this is the first report on this mutation. The clinical manifestations and gene variation characteristics of 39 previously reported SAS cases were analyzed together with this case. The findings of the present study suggested severely impaired language development, facial dysmorphism and varying degrees of delayed intellectual development as the characteristic clinical manifestations of SAS.