Cat eye syndrome

Cat eye syndrome
An example of the defect after which CES is named.
Classification and external resources
Specialty	medical genetics
OMIM	115470
DiseasesDB	29864
Orphanet	195

Cat eye syndrome (CES), or Schmid–Fraccaro syndrome, 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) (usually 3 times) 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. There is no significant reduction in life expectancy in patients who are not afflicted with one of CES' life-threatening abnormalities.

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.

History

The abnormalities common 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]

Characteristics

Xray image of anal atresia
Note that rectum ends blindly and the anus is not present

• Anal atresia (abnormal obstruction of the anus)
• Unilateral or bilateral iris coloboma (absence of tissue from the colored part of the eyes)
• Downward-slanting Palpebral fissures (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
• Intellectual disability – although most are borderline normal to mildly disabled, and a few even have normal intelligence, CES patients occasionally exhibit moderate to severe disability.
• Micrognathia (smaller jaw)
• Hernias
• Cleft palate
• Rarer malformations can affect almost any organ

References

1. 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.
2. Haab, O. Albrecht v Graefes. Archives of Ophthalmology, 24: 257 only, 1879
3. 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.
4. 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.

External links

• Cat Eye Syndrome International (CESI onlus): Official International Association for Cat Eye Syndrome