Diagnosis of one case of Williams-Beuren syndrome presenting with hypothyroidism by low-coverage massively parallel CNV sequencing

Objective To explore the clinical phenotypes and the genetic causes for a 5 years old boy with unexplained growth retardation,developmental delay,special face,and hypothyroidism.Methods Routine G-banding was performed to analyze the karyotype of the patient and his parents.In addition,whole exome sequencing and lowcoverage massively parallel CNV sequencing(CNV-seq)were used to determine the potentially pathogenic variants as well as the copy number variations(CNVs).