Related Experiment Videos
[Cat-eye syndrome. Clinical and cytogenetical differentialdiagnosis (author's transl)]
Insights
This study details a rare case of Cat-eye syndrome in a young girl, characterized by distinct physical anomalies and a unique supernumerary marker chromosome. Further cytogenetic analysis was unable to pinpoint the exact origin of this extra chromosome.
Area of Science:
- Genetics
- Developmental Biology
- Clinical Medicine
Context:
- Cat-eye syndrome (CES) is a rare genetic disorder characterized by a specific set of congenital anomalies.
- CES is typically associated with chromosomal abnormalities, often involving chromosome 22.
Purpose:
- To present a case study of a 5 1/2-year-old girl diagnosed with Cat-eye syndrome.
- To characterize the clinical presentation and perform detailed cytogenetic analysis of a supernumerary marker chromosome in this patient.
Summary:
- The patient exhibited classic CES symptoms including anal stenosis, preauricular tags/pits, iris coloboma, renal/ureteral duplication, and right-sided vesicourethral reflux, with normal mental development.
- Leukocyte alkaline phosphatase was normal. Chromosomal analysis revealed a supernumerary submetacentric chromosome, smaller than G-group chromosomes, with satellites on both arms.
- Advanced techniques like Giemsa banding, fluorescence, C-banding, and Giemsa-11 staining were used to analyze the marker chromosome, revealing specific banding patterns and heterochromatic segments, but its origin remained unidentified.
Impact:
- This case contributes to the understanding of Cat-eye syndrome variability and the cytogenetic complexities associated with supernumerary marker chromosomes.
- Highlights the limitations of current cytogenetic methods in definitively identifying the origin of novel marker chromosomes.
- Underscores the importance of comprehensive clinical and genetic evaluation in diagnosing rare genetic syndromes.
Abstract:
We report a 5 1/2-year-old girl whose clinical symptoms are consistent with diagnosis of the cat-eye syndrome. The prominent symptoms are: anal stenosis, preauricular tags and pits, coloboma of the iris, doubling of the pelvis and ureter on both sides, vesicourethral reflux on the right side and normal mental development. Leucocyte alkaline phosphatase is normal. Chromosomal analysis shows a supernumerary submetacentric chromosome. This extra chromosome is smaller than the G-group chromosomes and has satellites on the short and long arms. Autoradiography after 3H-thymidine incorporation shows a late-labeling marker chromosome. After using the Giemsa-banding technique, the chromatides demonstrate dark bandings with only soft, unstained satellites. With the fluorescence method, one can see spotlike fluorescence of the satellites on both arms and diffuse fluorescence of the hetero-chromatic segments. In addition, the C-bandings demonstrate a homogeneous dark staining of the chromatids, but we did not find stained satellites. Using the Giemsa-11 technique one can see the 47th chromosome with predominantly heterochromatic parts, but small euchromatic segments are visible between them. Satellites are unstained. Using currently accepted cytogenetical methods, it is not possible to identify the origin of this supernumerary marker chromosome.