Every time the unilateral retinoblastoma
parent has another child, the chance of that child developing retinoblastoma
is 7% to 15%. On the other hand, 85% to 93% of the offspring of
a unilateral retinoblastoma parent will not develop the disease.
than 95% of patients treated for retinoblastoma in the U.S.
than 90% of patients retain at least one eye
than 80% of the children keep 20/20 vision
blindness is unusual in children who have been successfully
treated for retinoblastoma
If neither parent had
The situation where neither parent has had retinoblastoma is the
most common and the most difficult to explain. Approximately one
out of every 100 patients who has retinoblastoma appears to somehow
destroy the tumor without treatment, or perhaps has a form of the
disease which is not capable of spreading. This is why both parents
are encouraged to have a dilated retinal exam. One percent of the
time, there is evidence of a cured or limited form of retinoblastoma
in the eye of a parent who was never aware of having had retinoblastoma
and was never treated for it. In that case, 45% of that parent's
children will develop retinoblastoma.
More confusing, and rarer, is
the possibility that a parent has the gene for retinoblastoma and
can pass it on to his or her children without having any evidence
of retinoblastoma in the eye. This is called the carrier state and
it means that the parent carries the gene but not the disease. In
this case, 45% of their children will be affected. Each of the examples
listed here explains how a parent who never had retinoblastoma can
have many children affected with bilateral retinoblastoma.
The most common situation
is where neither parent has the gene for retinoblastoma but has
a child born with retinoblastoma. If the parents are genetically
normal, the chance of another child having retinoblastoma is 1 in
15,000 to 1 in 20,000.
David H. Abramson,
“David H. Abramson, MD, FACS
Ophthalmic Oncology Service
Professor of Ophthalmology,
New York Eye and Ear Infirmary
New York Presbyterian Hospital-Weill Cornell Medical College
Manhattan Eye, Ear and Throat Hospital”