Identification of a novel frameshift variant in the SRCAP gene of a child with Floating-Harbor syndrome

Abstract

To explore the molecular basis for a child featuring with Floating-Harbor syndrome. The 2-year-and-8-month-old child presented with retarded growth and language development. Genomic DNA was extracted from peripheral blood samples from the child and his parents with informed consent and subjected to whole exome sequencing. Suspected variants were verified by Sanger sequencing. Pathogenecity of the variants were predicted by using bioinformatic tools. The child was found to carry a de novo frameshift variant c.7273dupA (p. Thr2425Asnfs*18) in the SRCAP gene. The variant was unreported previously and predicted to be pathogenic by MutationTaster. Analysis using HomoloGene system and MEGA software indicated position 2425 of the SRCAP protein to be highly conserved. Substitution of amino acid (Thr) at this position may cause destruction of three AT-hook domains (Amino acid 2857-2869, 2936-2948 and 3004-3016) and serious damage to the function of SRCAP protein. The patient's condition may be attributed to the de novo frameshift variant c.7273dupA (p. Thr2425Asnfs*18) of the SRCAP gene. Above finding can facilitate diagnosis of Floating-Harbor syndrome among Chinese population.