Identification of 1q21.1 Microduplication in a family

Objective: We have analyzed the clinical features of a child, with 1q21.1 microduplication syndrome, and done the literature review to study the correlation between 1q21.1 microduplica-tion and its phenotype. Methods: We summarized the patient’s medical history and the clinical symptoms, extracted the Genomic DNA from 2ml peripheral blood of the patient, her parents, elder brother, and sister. Then we performed the whole exon sequencing and the whole genome low-depth sequencing (CNV-seq). Results: The whole exon sequencing revealed that a 1.58 MB microduplication was detected in the CHR1:145883867-147465312 region, which was located in 1q21.1 region. The family analy-sis showed that the pathogenetic duplication fragment, which can also be detected in her elder brother’s DNA, originated from the mother. Conclusion: The patient was diagnosed with 1q21.1 microduplication syndrome through the clinical and genetic analysis. 1q21.1 microduplication syndrome is a rare copy number variant disease that can be manifested as multiple congenital developmental disorders. These include developmental delays, autism spectrum disorders, congenital malformations and congenital heart defects with genetic heterogeneity and various clinical manifestations. Compared with the traditional detection methods, the whole exon sequencing combined with qPCR can provide ac-curate molecular diagnosis for this type of children with genetic mutation, which is of great sig-nificance for genetic counseling and early intervention.