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Updated: Jul 5, 2026
09:16
Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants
Published on: February 21, 2015
Concurrent microdeletion and duplication of 22q11.2
E Blennow1, K Lagerstedt, H Malmgren
1Clinical Genetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. elisabeth.blennow@ki.se
Clinical Genetics
|May 1, 2008
Summary
A novel microduplication of 22q11.2, excluding the DiGeorge critical region (DGCR), was identified. This genetic finding in a young girl suggests mild or no symptoms associated with this specific duplication.
Area of Science:
- Genetics
- Molecular Biology
- Human Genetics
Background:
- Microduplications of 22q11.2 are rare genetic alterations.
- Most reported cases involve the DiGeorge critical region (DGCR).
Observation:
- A unique 22q11.2 microduplication, not encompassing the DGCR, was identified in a young girl.
- The patient presented with features of velocardiofacial syndrome, including velopharyngeal insufficiency and learning difficulties, but lacked congenital malformations.
- Mosaicism for a DGCR deletion was also detected in her peripheral blood lymphocytes.
Findings:
- Array comparative genomic hybridization (CGH) and interphase fluorescent in situ hybridization (FISH) characterized the deletion and duplication.
- The identified 22q11.2 duplication appears novel and is associated with minimal or no clinical symptoms.
- The study highlights the role of low-copy repeats in mediating 22q11.2 rearrangements.
Implications:
- This case expands the understanding of 22q11.2 deletions and duplications.
- It suggests that specific 22q11.2 duplications outside the DGCR may have a milder phenotypic impact.
- Further research is needed to fully elucidate the genotype-phenotype correlations in 22q11.2 disorders.
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