Alyhia's Eye

Introduction

Coloboma Syndrome or Cat Eye Syndrome (to be more specific) is malformation to the eye. It is caused by an inverted 22 and with a break in 22q11 (scientific terminology). This is a defect that is most commonly inherited although it can form due to other factors. It can cause many health problems related to more than just vision. It can affect sight, hearing, cause heart problems, kidney problems, growth disabilities, mental disabilities, and much more. One way to identify this syndrome is to do genetic testing.

Part One

Coloboma is a very rare disease. In Switzerland only about 1 in every 50,000 – 150,000 live births have this malformation. However a recent study suggests that 1 in about 7400 people have this disorder (Nicks, 2011). It was first described in 1879 by Dr. O. Haab. Later more information was gathered to know its cause stemmed from the 22 chromosome. This defect led the eye to be abnormally shaped.

History

O. Haab, a Switzerland ophthalmologist, was the first to describe a syndrome where anal atresia (another possible symptom) combined with Coloboma in 1879 (Bissonnette & Dalens, 2006).  An extra bisatellited marker chromosome was found in patients with CES, in 1965 (Chen, 2006). However, the name “Cat Eye Syndrome” (CES) was created by the two men, W. Schunid from Zurich, Switzerland and M. Fraccaro from Pavia, Italy. They discovered that it was caused by too many of the 22 Chromosome (Bissonnette & Dalens, 2006). Obviously its name came about due to the shape of the pupil (explained in more depth later on in this section).

Cause

The cause of this mutation lives within the 22^nd chromosome. For starters, individuals who do not have CES have two 22^nd chromosomes. Both chromosomes have a long arm known as 22q and a short arm know as 22p. However, the 22^nd chromosome for individuals who do have CES also have the 22p present along with the short region of the 22q three or four times instead of just twice (NORD, 2010). The extra 22 chromosome usually comes from one of the parents (Bissonnette & Dalens, 2006), making this an inherited gene which is present at birth (Nicks, 2011). (Please refer to table one in Appendix A for a more detailed layout of the 22^nd chromosome.) “Treatment is given according to the symptoms the individual is diagnosed with. Doctors recommend surgery to repair inborn defects in the heart or anus. Patients with short stature are given growth hormone therapy” (Nicks, 2011, pg1).

Identify

So how is it determined if someone has Cat Eye Syndrome? One way is through a genetic type of testing which is called FISH (Fluorescence in Situ Hybridisation). “FISH is a relatively new molecular cytogenetics technology utilizing fluorescently labeled DNA probes to detect or confirm gene or chromosome abnormalities that are generally either beyond the resolution of routine cytogenetics or can be applied to samples that are unsuitable for conventional cytogenetics analysis” (HMDS, 2005, pg1). Syndromes such as coloboma, anal atresia, and preauricular pits/tags (go into more detail later on) can lead to a Cat Eye Syndrome diagnose. However, the FISH test is what narrows it down to Cat Eye Syndrome specifically.

Part Two

Cat Eye Syndrome has many external symptoms such as the shape of the eye (‘s). There are also internal complications that can arise from this syndrome such as heart complications. While this syndrome may seem very daunting at times we will get the chance to look at a young lady, Alyhia, who is a lighter side to the possible outcomes that can occur due to this syndrome.

External Symptoms

There are many external symptoms that can occur due to CES. The most obvious one is the shape of the pupil; to be more specific the hypertelorism, down-slanting papebral in one or two eyes or total/partial inferior Coloboma of iris choroid and retina. Of those that have this syndrome a minority are microcephalic, which is a small head and undeveloped brain (internal). Less than 50% of patients show growth retardation. Patients with this syndrome can exhibit preauricular, ears with pits, tags, or both (which is most common). They also have absent canals causing severe hearing loss and they can have sensorineural hearing loss which can be severe or mild. These are a few of the external symptoms resulting from CES (Gorlin, Cohen, & Hennekarn, 2001).   

Internal Symptoms

There are many internal symptoms that can occur due to CES. To start off, there is a chance of mild to moderate mental impairment. Thirty-five percent of those with CES have congenital heart malformations. Fifty percent of those with CES have renal anomalies; most consist of horseshoe kidneys, congenital hydronephrosis, or unilateral agenesis/hypoplasia. Less than 35% have anal atresia and those who do, always have it with a fistula into the bladder, vagina perineum, or urethra. Some individuals with CES have covered or anteriorly displaced anus. Males who have CES may have cryptorchidism. Those are some of the internal symptoms that can occur for individuals who have CES (Gorlin, Cohen, & Hennekarn, 2001). 

Alyhia

There are many down sides to CES and although it is very rare, individuals born with this syndrome can have a multitude of problems. However, that is not to say that every single individual is endowed with several of the inflictions listed on page nine. One example of this is a baby girl (Alyhia), now five months old, who has CES. Alyhia was born two weeks early on November 7, 2010. She was small, at five pounds zero ounces and 17 inches in length. However, at the age of five months she is now 12 pounds 7 ounces and 22 inches. She has developed quite a bit since her birth, both mentally and physically.  So far she shows no other symptoms except that of Coloboma in her left eye. Her left eye is shaped like that of a cat and she has slight sensitivity to sun light. Alyhia is only five months old so it is hard to say for sure that she is free and clear of all ailments. At this time her health is good. Her parents are proud and expect her to do great things. They love her eye and say that it makes her even more special and unique. They thank God every day for the mild symptoms their daughter shows and prays that it will stay that way (Anonymous).  

Conclusion

Cat Eye Syndrome is a malformation of the pupil that gives it the look of a cat’s eye (although it can vary). This syndrome is caused because there are three or four of the 22nd chromosome. It was first discovered in 1879, although it was not named until sometime later when two men discover the extra(s) chromosome(s). It can be identified through the FISH method of examining the chromosomes. It is a Syndrome that can cause many symptoms both external and internal. While this syndrome varies from mild to extreme, one thing is true, they all have something extra. It is advised that anyone showing any signs of symptoms should see a doctor as soon as possible.

References

Cohen, M. M., Hennkam, R. C., Golin, R. J. (2001). Syndromes of the Head and Neck. USA: Oxford University Press.

Chen, H. (2006). Atlas of Genetic Diagnosis and Counseling. Totown, New Jersey: Humana Press.

Bissonnette, B., Dalens, B. J. (2006). Syndromes: Rapid Recognition and Preoperative  Implications. USA: McGraw-Hill Professional.

Haematological Malignancy Diagnostic Service. (1999-2004). Fluorescence in Situ Hybridisation (FISH). Retrieved from: http://www.hmds.org.uk/fish.html

National Organization for Rare Disease. (12/31/2010). Cat Eye Syndrome. Retrieved from: http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Cat%20Eye%20S    ndrome

Nicks, J. (2011). Cat Eye Syndrome. Retrieved from: http://www.buzzle.com/articles/cat-eyesyndrome.html