Cat eye syndrome
| Cat eye syndrome | |
|---|---|
| Classification and external resources | |
| OMIM | 115470 |
| DiseasesDB | 29864 |
Cat Eye Syndrome (aka. CES) is a rare condition caused by the short arm (p) and a small section of the long arm (q) of human Chromosome 22 being present three (trisomic) or four times (tetrasomic) instead of the usual two times.[1] The term "Cat Eye" syndrome was coined because of the particular appearance of the vertical colobomas in the eyes of some patients. However, over half of the CES patients in the literature do not present with this trait.[citation needed] There is no significant reduction in life expectancy in patients who are not afflicted with one of CES' life threatening abnormalities.
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[edit] Genetics
The additional chromosome 22 usually arises spontaneously. It may be hereditary and parents may be mosaic for the marker chromosome but show no phenotypic symptoms of the syndrome.
The chromosomal area included in the Cat Eye Syndrome "critical region" is 22pter→q11.
[edit] History
The abnormalities common to to cat eye syndrome were first cataloged in 1898.[2] It was described in association with a small marker chromosome in 1965.[3] Early reports of Cat Eye Syndrome discuss the possibility of chromosome 13 involvement. Now, CES is considered to be present with the chromosome 22 trisomy findings.[4]
[edit] Characteristics
- Anal atresia (abnormal obstruction of the anus)
- Unilateral or bilateral iris coloboma (absence of tissue from the colored part of the eyes)
- Palpebral fissures (downward slanting openings between the upper and lower eyelids)
- Preauricular pits/tags (small depressions/growths of skin on the outer ears)
- Cardiac defects (such as TAPVR)
- Kidney problems (missing, extra, or underdeveloped kidneys)
- Short stature
- Scoliosis/Skeletal problems
- Mental retardation -- although most are borderline normal to mildly retarded, and a few even have normal intelligence, CES patients occasionally exhibit moderate to severe retardation.
- Micrognathia (smaller jaw)
- Hernias
- Cleft palate
- Rarer malformations can affect almost any organ
[edit] References
- ^ Rosias PR, Sijstermans JM, Theunissen PM, et al. (2001). "Phenotypic variability of the cat eye syndrome. Case report and review of the literature". Genet. Couns. 12 (3): 273–82. PMID 11693792.
- ^ Haab, O. Albrecht v Graefes. Arch. Ophthal. 24: 257 only, 1879
- ^ Schachenmann G., Schmid W., Fraccaro M., et al. (1965). "Chromosomes in Coloboma and Anal Atresia". Lancet 2 (7406): 290. doi:10.1016/S0140-6736(65)92415-3. PMID 14330081.
- ^ Bühler EM, Méhes K, Müller H, Stalder GR (1972). "Cat-eye syndrome, a partial trisomy 22". Humangenetik 15 (2): 150–62. doi:10.1007/BF00295742. PMID 5049068.
