Retinoblastoma: Causes and Risk Factors

Retinoblastoma is a rare eye cancer that is almost always diagnosed in children under the age of 5. Doctors aren’t always able to pinpoint risk factors or risk factors for retinoblastoma, but genetic biomarkers are known to cause the disease.

Research is still ongoing to understand the processes that induce tumor growth in retinoblastoma. Patients and caregivers can learn a lot about the pathology (medical causes and effects) of their disease from laboratory results.

Where does retinoblastoma occur

Retinoblastoma starts at the back of the eye, in the retina, as a thin layer of light-sensitive tissue, and continues to grow from there.

white pupil, or Leukocytosisis caused by light reflecting off the white surface of the tumor as it grows.

crossed eyes (squint), bulging eyeballs (Proptosis) or enlargement of the eyeball (naked eye) and accumulation of inflammatory cells (hyphema) are both caused by a growing tumor as it squeezes out and moves out of part of the eye.

When trying to understand the diagnosis of retinoblastoma, it may be helpful to have a good understanding of the anatomy of the eye.

What causes retinoblastoma?

Retinoblastoma is almost always inherited, whether inherited (passed from parent to child) or spontaneous (occurring without outside influence). Researchers are still exploring what drives nerve cells to mutate into this rare eye cancer, but doctors know it’s most likely triggered by a random error in gene transcription (the development of genes) that creates an error in the cell. instruction.

When this genetic error occurs, the DNA in the cells of the eye is damaged. This can cause cells to grow out of control, forming a mass or tumor. In addition, cancer cells have been unprogrammed to die when healthy cells are born and die to make room for new cells. This further leads to uncontrolled growth and spreading (metastasis).

Can retinoblastoma develop in adults?

Retinoblastoma is so rare in adults that statistics are scarce. Because of an inherited mutation, scientists believe that the patient may have reappeared years ago with an undetected childhood retinoblastoma that went into remission. In these cases, the original tumor is called a retinocytoma or retinal tumor.

RB1 gene mutation

Scientists have identified mutations in the RB1 gene as one of the leading causes of retinoblastoma. In fact, RB1 mutations cause the majority of retinoblastoma cases. Doctors rarely find other gene mutations in people with retinoblastoma. In rare cases, retinoblastomas are caused by mutations in the MYCN gene rather than the RB1 gene. Even rarer, doctors find no genetic mutation at all and cannot determine any cause.

There is a relationship between how the mutation occurs (inherited versus spontaneous) and where the mutation occurs (in one eye, both eyes, and the pineal gland, a small endocrine gland in the brain). Here is an overview;

  • Unilateral (occurring in one eye): In nearly 85 percent of children with retinoblastoma in only one eye (unilateral), a genetic change called a germline mutation occurs spontaneously. This means doctors don’t know why it popped up (it wasn’t inherited from a parent) and caused cancer.
  • Bilateral (occurring in both eyes): In another 15% of cases, retinoblastoma is present in both eyes (bilateral), and a genetic mutation has been passed from parent to child that causes the tumor to grow. Even if the parents themselves have never actually had retinoblastoma, in these cases, they can pass on susceptibility (the likelihood of the disease) to their children.
  • Trilateral (occurs in both eyes and pineal gland): A third type of disease, trilateral retinoblastoma, begins in the pineal gland and develops in both eyes. Trilateral retinoblastoma is always inherited from one or both parents.

How mutations affect cells

Whether in one or both eyes, one-third of people with retinoblastoma inherit a genetic mutation. In people with inherited retinoblastoma, the RB1 mutation is present in every cell in their body. In the other two-thirds of people whose mutations occurred spontaneously, most had the RB1 gene mutation in only some of their cells, not all of them.

risk factor

No other causes of retinoblastoma have been identified other than genetic mutations, and scientists have not demonstrated that any environmental or lifestyle factors can cause it. Research into suspected risk factors is ongoing.

Aside from genetic mutations, the only known risk factor for retinoblastoma is very young age. Most children diagnosed with retinoblastoma are under the age of 5, and many are even infants. Children of all races have nearly equal odds of developing retinoblastoma, although children living in underserved communities tend to have worse outcomes for the disease due to health care restrictions.

Racial and ethnic health disparities exist in every state, report finds

Scientists are still studying whether other factors increase the risk of retinoblastoma. Factors actively suspected and under study include:

  • Older father’s age at birth (there is a greater risk of genetic damage to sperm as you age)
  • Father had previous exposure to radiation
  • Mother’s exposure to gasoline or diesel exhaust during pregnancy
  • Pregnant women diet low in fruits and vegetables

Risk is not the cause

It’s important to remember that even though scientists have shown that these factors increase a child’s risk of developing retinoblastoma, risk factors are not the cause. It just makes the child slightly more likely to develop the disease.

Scientists believe that the etiology of retinoblastoma is largely random and often unpredictable. Once a parent receives a diagnosis of retinoblastoma, the most important thing is to focus on understanding the disease and how to treat it.


Retinoblastoma is a rare eye cancer that originates in the retina. It is mostly diagnosed in children under the age of 5. Retinoblastoma is caused by inherited or spontaneous genetic mutations. Scientists have identified mutations in the RB1 gene as one of the main causes of retinoblastoma, but other genetic mutations are also possible.

Other than age, there are no known lifestyle risk factors for the development of retinoblastoma.

VigorTip words

People often wonder what causes illness, what they can do to prevent it, and how to prevent illness in other family members. It is important for parents not to blame themselves for genetic abnormalities. Knowing why is important because genetic testing can let you know if your child’s disease is unilateral or bilateral, while the other eye is at risk. It can also reveal whether other family members may be at risk.

A cancer diagnosis can be very stressful for families. Self-care is very important for both parents and children. This can be in the form of meditation, support groups, or going out with friends to decompress.

Cancer Support Groups and Communities

Frequently Asked Questions

  • What is retinoblastoma?

    Retinoblastoma is a rare cancer that originates in the retina of the eye, the thin layer of tissue at the back of the eye that helps process light. Of the children diagnosed with the disease, one in four developed the disease in both eyes, and three out of four developed cancer in one eye.

  • What causes retinoblastoma?

    Retinoblastoma is caused by mutations in genes involved in eye development. It can spread in families where children inherit the mutation from parents who may or may not have the disease themselves. It can also appear spontaneously.

  • Can retinoblastoma be prevented?

    Currently, doctors don’t know of any way to prevent retinoblastoma, but early detection and treatment can greatly improve outcomes.

  • Are there risk factors for retinoblastoma?

    Scientists have not demonstrated the existence of risk factors for developing retinoblastoma, other than age (under 5 years) or genetic mutations.

  • What causes retinoblastoma to spread?

    Without treatment, retinoblastoma cells will continue to multiply and will almost certainly spread to the other eye or other parts of the body, making it more difficult to treat. If you notice any whites in your pupils, crossed eyes, lazy eyes, eye discomfort, or any visual disturbance, schedule an eye exam right away so you can catch and treat the condition early.

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