Molecular diagnosis of children with unexplained intellectual disability/ developmental delay by array-CGH

HE Xi-Yu; CHEN Xiao-Chun; LI Ran; LI Pei; LU Ai-Mei

doi:10.7499/j.issn.1008-8830.2015.05.009

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Chinese Journal of Contemporary Pediatrics ›› 2015, Vol. 17 ›› Issue (5) : 459-463. DOI: 10.7499/j.issn.1008-8830.2015.05.009

CLINICAL RESEARCH

Molecular diagnosis of children with unexplained intellectual disability/ developmental delay by array-CGH

HE Xi-Yu, CHEN Xiao-Chun, LI Ran, LI Pei, LU Ai-Mei

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Abstract

Objective To analyze the potential pathogenic genomic imbalance in children with unexplained intellectual disability (ID) and/or developmental delay (DD) and its association with phenotypes, and to investigate the value of array-based comparative genomic hybridization (array-CGH) in clinical molecular genetic diagnosis.Methods The whole genome of 16 children with ID/DD was scanned by the array-CGH for detection of genomic copy number variations (CNVs), and the revealed genomic imbalance was confirmed by multiplex ligation-dependent probe amplification. Results G-band karyotyping of peripheral blood cells showed no abnormalities in the 16 children. The results of the array-CGH revealed that 6 (38%) of the 16 patients had genomic CNVs, and 3 cases of CNVs were normal polymorphic changes; 1 CNV was a microdeletion of 4p16.3, which was the critical region for Wolf-Hirschhorn syndrome, and 1 CNV was a microdeletion of 7q11.23, which was the critical region for Williams-Beuren syndrome. Moreover, a CNV was identified with two duplications at 2q22.2 and 15q21.3 in a boy, which proved to have a clinical significance due to its association with ID, brain DD, unusual facies, cryptorchidism, irregular dentition, etc. Conclusions Array-CGH allows for the etiological diagnosis in some of the children with unexplained ID/DD. As a high-throughput and rapid tool, it has a great clinical significance in the etiological diagnosis of ID/DD.

Key words

Array-based comparative genomic hybridization / Intellectual disability / Developmental delay / Genomic imbalance / Child

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HE Xi-Yu, CHEN Xiao-Chun, LI Ran, LI Pei, LU Ai-Mei. Molecular diagnosis of children with unexplained intellectual disability/ developmental delay by array-CGH[J]. Chinese Journal of Contemporary Pediatrics. 2015, 17(5): 459-463 https://doi.org/10.7499/j.issn.1008-8830.2015.05.009

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