Objective: To analyze the clinical and molecular genetics features of a family affected with Say-Barber-Biesecker-Young-Simpson syndrome (SBBYSS).
Methods: High-throughput sequencing was used to detect copy number variations (CNVs) and pathogenic variant within the whole exome of the affected child.
Results: No pathogenic CNV was found in the child, while exome sequencing identified a heterozygous c.3367_c.3370delAGAA (p.Arg1123Argfs*6) frameshifting variant in the exon 16 of the KAT6B gene. The same variant was not found in either parent.
Conclusion: The c.3367_c.3370delAGAA (p.R1123Rfs*6) probably underlies the disease in the affected child. Above finding has facilitated genetic counseling and prenatal diagnosis for the family.