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Phenotypic variability of Cat-Eye syndrome
M J Berends1, G Tan-Sindhunata, B Leegte
1Department of Medical Genetics, University of Groningen, The Netherlands. A.J.van.Essen@medgen.azg.nl
Genetic Counseling (Geneva, Switzerland)
|May 3, 2001
Summary
Cat-Eye syndrome (CES) is a rare genetic disorder characterized by a specific chromosomal abnormality, inv dup(22). Phenotypic variability is significant, making diagnosis challenging based on symptoms alone.
Area of Science:
- Genetics
- Developmental Biology
- Clinical Medicine
Background:
- Cat-Eye syndrome (CES) is a rare genetic disorder.
- It is characterized by a specific chromosomal abnormality: an inverted duplication of chromosome 22 (inv dup(22)).
- Key features include iris coloboma and anal atresia, but presentation is highly variable.
Observation:
- This study reports on three CES patients with inv dup(22) identified via FISH analysis.
- A review of 71 CES patients reveals significant phenotypic variability.
- Only 41% of patients exhibit the classic triad of iris coloboma, anal, and pre-auricular anomalies.
Findings:
- The exact cause of phenotypic variability in CES remains unknown.
- Mild to moderate mental retardation affects 32% of CES patients, occurring more frequently in males.
- No distinct phenotypic differences are observed between mentally retarded and non-retarded CES patients.
Implications:
- The high degree of phenotypic variability complicates clinical recognition of CES.
- Further research is needed to understand the genetic and molecular factors driving CES variability.
- Accurate cytogenetic diagnosis is crucial for identifying CES patients who may not present with typical features.