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Updated: Jul 5, 2026
07:34
FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
Cryptic trisomy 5q35.2qter and deletion 1p36.3 characterised using FISH and array-based CGH
Eda G Utine1, Yasemin Alanay, Dilek Aktas
1Clinical Genetics Unit, Department of Pediatrics, Hacettepe University, Ankara, Turkey. geutine@hacettepe.edu.tr
European Journal of Medical Genetics
|April 29, 2008
Summary
A complex genetic abnormality, including a marker chromosome and deletions/duplications, caused a boy's developmental delays and distinct physical features. Advanced genetic testing was crucial for diagnosis.
Area of Science:
- Human Genetics
- Cytogenetics
- Developmental Biology
Background:
- A 10-year-old boy presented with global developmental delay and dysmorphic features.
- Initial cytogenetic analysis revealed an extra marker chromosome of paternal origin.
Observation:
- Multicolour fluorescence in situ hybridization (FISH) identified the marker chromosome as derived from chromosome 15.
- Array-based comparative genomic hybridization (aCGH) detected a duplication on chromosome 5 (dup(5)(q35.2qter)) and a deletion on chromosome 1 (del(1)(p36.3)).
- Parental FISH confirmed the complex chromosomal rearrangement occurred de novo.
Findings:
- The patient's phenotype resulted from a complex, cryptic chromosomal abnormality.
- A combination of cytogenetic techniques was necessary to fully elucidate the aberration.
- The identified genetic imbalances correlate with the observed clinical presentation.
Implications:
- This case highlights the importance of comprehensive genetic analysis for diagnosing complex developmental disorders.
- Advanced molecular cytogenetics is essential for uncovering cryptic chromosomal aberrations.
- Understanding such complex rearrangements aids in genetic counseling and future research.
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