What is Retinoblastoma – Causes and Symptoms
Retinoblastoma is a rare type of eye cancer. It mostly affects children below the age of 5 years. According to the statistics of the National Cancer Institute, 300 children and adolescents under the age of 20 years are diagnosed with this cancer in the United States, every year. It accounts for only 3 percent of all cancers in children under 15 years, 11 percent of cancers affecting children below one year. Though this cancer targets one eye, in one out of every three cases, it is found that the disease spreads to the other eye as well. This article tries to understand the causes and symptoms of this dreadful form of cancer in children.
Causes of Retinoblastoma:
- Retina is a specialized light-sensitive tissue located at the back of the eye. It detects light and color.
- Cell growth and division of this tissue is regulated by a gene called the RB1 gene.
- There are several factors which can change the chemical structure of this gene, technically known as mutation process.
- It is this mutation process of the RB1 gene which causes most of the cases of retinoblastoma.
- Changes in the structure leads to abnormality in the functioning of the gene.
- It allows the growth and division of malignant cancer cells in the retina in an uncontrollable manner forming the tumor.
- Genes are the chemical instructions followed by any cell type in the body to function normally.
- A set of these genes is known as a chromosome. The gene RB1 is present in chromosome 13.
- In some cases of this cancer, deletion of certain region of this chromosome can also cause this cancer.
- When this cancer causes gene mutation in the whole body, the condition is known as germinal retinoblastoma.
- 40 percent of the cases of retinoblastoma involves germimal retinoblastoma. In such a case, the cancer can be inherited.
Symptoms of Retinoblastoma:
- Cross eyed
- Vision loss
- Eye inflammation
- Retinal tumor
- Unusual glint in eye
- Vision loss in one eye
- White looking pupil
- Calcification of eyeball