Noonan syndrome with multiple lentigines (brown spots on skin), formerly called
Noonan syndrome with loose anagen hair (hair in its active growth phase)
What Causes RASopathies?
The body's protein cells communicate with each other in many ways. Good communication
ensures the cells work as they should. When groups of proteins communicate with each
other, they create a pathway. The signals the cells send along the
pathway can cause them to:
copy themselves to make more cells
die off when the body doesn't need more cells
work in a different way
Changes in the genes (our genetic "blueprints") in the RAS pathway cause the RASopathies.
These happen when there's a problem in one of the steps in the pathway. Cells react
in ways they shouldn't — for instance, multiplying when they should die off.
Sometimes, a RASopathy runs in families. A parent who has one has a 50% chance
of passing it to a child. Other times, the change is "spontaneous." This means that
a child has the condition but the parents do not. This is called a new mutation.
What Else Should I Know?
The problems caused by RASopathies vary. Even children with the same condition
can have differences in the problems it causes and how severe the problems are.
Children with RASopathies are cared for by a health care team that includes specialists
RASopathies are lifelong conditions. But medical care can help with many of the
symptoms and problems they cause.