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07:34
FISH for Pre-implantation Genetic Diagnosis
Published on: February 23, 2011
Blaschkolinear malformation syndrome in complex trisomy-7 mosaicism
E Magenis1, M J Webb, B Spears
1Department of Molecular and Medical Genetics, Child Development and Rehabilitation Center, Oregon Health Sciences University, Portland, Oregon 97201-2998, USA.
American Journal of Medical Genetics
|December 14, 1999
Summary
Chromosomal mosaicism was identified in skin biopsies of a boy with growth issues and developmental delays, despite normal blood chromosome tests. This mosaicism, involving chromosome 7 and a ring chromosome, explains his asymmetry and growth patterns.
Area of Science:
- Genetics
- Developmental Biology
- Human Physiology
Background:
- Intrauterine growth retardation (IUGR) and short stature are common pediatric concerns.
- Chromosomal abnormalities can lead to developmental delays and physical anomalies.
- Diagnosing chromosomal mosaicism can be challenging, especially when limited to specific tissues.
Observation:
- A boy presented with IUGR, short stature, moderate mental retardation, and minor anomalies.
- Initial peripheral blood chromosome studies were normal.
- Distinctive skin pigmentation patterns (swirls, streaks) and body asymmetry suggested chromosomal mosaicism.
Findings:
- Skin biopsies revealed mosaicism with normal cells, trisomy 7, and a small ring chromosome.
- Fluorescence in situ hybridization (FISH) confirmed trisomy 7 and the ring's origin from chromosome 7.
- One biopsy showed an additional cell line with both trisomy 7 and the ring chromosome.
Implications:
- Aneuploidy (trisomy 7) likely contributed to growth retardation.
- Tissue-limited mosaicism, reflected in asymmetry, should be considered in diagnosing such cases.
- Early suspicion of mosaicism could lead to earlier diagnosis and intervention for related developmental issues.
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