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Updated: Jul 6, 2026
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Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants
Published on: February 21, 2015
Array comparative genomic hybridization in global developmental delay
M I Shevell1, B A Bejjani, M Srour
1Department of Pediatrics, McGill University, Montreal, Quebec, Canada. michael.shevell@muhc.mcgill.ca
Summary
Array-based comparative genomic hybridization (CGH) identified genetic causes in 6.4% of children with unexplained global developmental delay (GDD). This technology shows diagnostic value for identifying DNA copy number changes in pediatric cases.
Area of Science:
- Genetics
- Pediatrics
- Genomic Medicine
Background:
- Global developmental delay (GDD) affects children with undiagnosed neurodevelopmental conditions.
- Array comparative genomic hybridization (array CGH) is a technology for detecting DNA copy number changes (CNCs).
- Previous standard genetic tests like karyotyping often yield non-diagnostic results in GDD cases.
Purpose of the Study:
- To evaluate the diagnostic yield of array CGH in children with unexplained non-syndromal GDD.
- To identify the prevalence of pathogenic copy number changes in this pediatric cohort.
Main Methods:
- Array CGH was performed on 94 children with well-defined GDD and non-diagnostic prior testing.
- Abnormalities were confirmed using fluorescence in situ hybridization (FISH) and parental testing.
- Clinical factors were analyzed to predict the likelihood of identifying pathogenic CNCs.
Main Results:
- Array CGH detected a causally related pathogenic CNC in 6.4% (6/94) of the children studied.
- Three of the identified CNCs were located in sub-telomeric regions.
- Minor dysmorphic features (<3) were predictive of a positive CGH finding, unlike the severity of developmental delay.
Conclusions:
- Array CGH offers a 6.4% etiologic yield for children with unexplained non-syndromal GDD.
- This technology is valuable for diagnosis when used after initial clinical evaluation and targeted testing.
- Array CGH may be considered a primary diagnostic tool for unexplained GDD in children.
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