This web page was produced as an assignment for Genetics 677, an undergraduate course at UW-Madison
Future Directions
Why the eye?
It is not currently known why an eye cancer develops from a mutation in a gene that is important all over the body. Further investigation into this phenomenon is necessary and may help to elucidate pathways that are present in other heritable cancers.(1)
This can be done by looking at the differences between eye tissue and the other types of tissue that express the Rb1 gene. One of the tools that could be used is to collect micro array data on the differences between eye tissue and the other tissues. This can be done in humans, but a more feasible method would be to study an organism with a homolog of Rb1. When looking at the Rb1 protein interaction map of the rat, one can see that it would be a good candidate to do studies on.(2)
Diagnosis
The current most prevalent way that retinoblastoma is recognized in children is the noticing of leukocoria, the whiteness of the eye due to a tumor being in the eye when the flash of a camera hits the eye. See the picture below for an example.(3)
As a result of this, the tumor has already formed when most children are diagnosed with retinoblastoma. The result of this is that the most common method of treatment for retinoblastoma is enucleation, or the complete removal of the eye. This is done to ensure that the cancer has not gone metastatic and spread to other tissues of the body. This, of course, results in the child having to live their life with only one eye. Earlier detection methods have to be improved in order to prevent this.(3)
The main problem with the testing is that the most convenient way to test if someone is prone to the development of retinoblastoma is to take a blood sample and look for chromosomal abnormality, however noticable chromosomal abnormality only occurs in about 5-8% of cases, making it an unrealistic diagnosis technique.(1)
It is not currently known why an eye cancer develops from a mutation in a gene that is important all over the body. Further investigation into this phenomenon is necessary and may help to elucidate pathways that are present in other heritable cancers.(1)
This can be done by looking at the differences between eye tissue and the other types of tissue that express the Rb1 gene. One of the tools that could be used is to collect micro array data on the differences between eye tissue and the other tissues. This can be done in humans, but a more feasible method would be to study an organism with a homolog of Rb1. When looking at the Rb1 protein interaction map of the rat, one can see that it would be a good candidate to do studies on.(2)
Diagnosis
The current most prevalent way that retinoblastoma is recognized in children is the noticing of leukocoria, the whiteness of the eye due to a tumor being in the eye when the flash of a camera hits the eye. See the picture below for an example.(3)
As a result of this, the tumor has already formed when most children are diagnosed with retinoblastoma. The result of this is that the most common method of treatment for retinoblastoma is enucleation, or the complete removal of the eye. This is done to ensure that the cancer has not gone metastatic and spread to other tissues of the body. This, of course, results in the child having to live their life with only one eye. Earlier detection methods have to be improved in order to prevent this.(3)
The main problem with the testing is that the most convenient way to test if someone is prone to the development of retinoblastoma is to take a blood sample and look for chromosomal abnormality, however noticable chromosomal abnormality only occurs in about 5-8% of cases, making it an unrealistic diagnosis technique.(1)
Figure 1
The next step is for the genetic tests necessary for testing for susceptibility to retinoblastoma to become cheap enough that testing every newborn child is feasible. At the moment the cost of the tests, coupled with the rarity of the disease, causes it to be viewed as a non issue when it comes to pre-emptive testing.
References
1.Retinoblastoma: the disease, gene and protein provide critical leads to understand cancer. DiCiomma D. et al. seminars in CANCER BIOLOGY, Vol. 10, 2000: pp. 255–269
2.Knudson 1971, Proc Acad Nat Sci USA68:820
3.Lohmann DR, Gallie BL (2004). "Retinoblastoma: revisiting the model prototype of inherited cancer.". American journal of medical genetics. Part C, Seminars in medical genetics 129 (1): 23–8.
4. Figure 1: http://www.stjude.org/Images/misc-retinoblastoma-0602.jpg
2.Knudson 1971, Proc Acad Nat Sci USA68:820
3.Lohmann DR, Gallie BL (2004). "Retinoblastoma: revisiting the model prototype of inherited cancer.". American journal of medical genetics. Part C, Seminars in medical genetics 129 (1): 23–8.
4. Figure 1: http://www.stjude.org/Images/misc-retinoblastoma-0602.jpg
