Application of single nucleotide polymorphisms array in the diagnosis of chromosome abnormality-cytogenetic analysis of a family with Williams-Beuren syndrome

Abstract

Objective To explore the value of single nucleotide polymorphisms array (SNP array) in diagnosing chromosomal abnormalities. Methods SNP array and qPCR were used to analyze the whole genome DNA of a pair of mentally retarded father and son for high-resolution analysis. The correlation between the phenotypes and chromosomal abnormalities was analyzed, and the source of chromosomal abnormalities was determined in this child. Results The chip karyotypes of both the father and the son are arr[hg19]7q11.23(72722981-74138121)×1. The child inherited chromosome 7 abnormality from his father, which was closely related to the clinical manifestations of the two patients. Conclusion The deletion of approximately 1.42 Mb from chromosome 7 resulted in the clinical presentation of Williams-Beuren syndrome. By means of high-resolution SNP array technology, the source of abnormal fragments of the child was identified and detailed, and accurate chromosomal information was provided, which was helpful to clarify the correlation between clinical symptoms and patients’ genetic abnormalities, and at the same time to assess the risk of recurrence of chromosomal abnormalities. Key words: Williams-Beuren syndrome; Single nucleotide polymorphisms array; Chromosomal abnormality