J Genet Med.  2021 Jun;18(1):31-37. 10.5734/JGM.2021.18.1.31.

Clinical utility of chromosomal microarray analysis to detect copy number variants: Experience in a single tertiary hospital

• Park HS
• Kim A
• Shin KS
• Son BR

• KMID: 2517209
• DOI: http://doi.org/10.5734/JGM.2021.18.1.31

Abstract

Purpose
To summarize the results of chromosomal microarray analysis (CMA) for copy number variants (CNVs) detection and clinical utility in a single tertiary hospital.
Materials and Methods
We performed CMA in 46 patients over the course of two years. Detected CNVs were classified into five categories according to the American College of Medical Genetics and Genomics guidelines and correlated with clinical manifestations.
Results
A total of 31 CNVs were detected in 19 patients, with a median CNV number per patient of two CNVs. Among these, 16 CNVs were classified as pathogenic (n=3) or likely pathogenic (LP) (n=11) or variant of uncertain significance (n=4). The 16p11.2 deletion and 16p13.11 deletion classified as LP were most often detected in 6.5% (3/46), retrospectively. CMA diagnostic yield was 24.3% (9/37 patients) for symptomatic patients. The CNVs results of the commercial newborn screening test using next generation sequencing platforms showed high concordance with CMA results.
Conclusion
CMA seems useful as a first-tier test for developmental delay with or without congenital anomalies. However, the classification and interpretation of CMA still remained a challenge. Further research is needed for evidence-based interpretation.

Keyword

Chromosome microarray analysis; Copy number variations; Developmental disability; Genetic testing; Highthroughput nucleotide sequencing