Do other members of your extended family have low platelets?
Sometimes people are diagnosed with ITP when they have an entirely different disease, inherited or familial thrombocytopenia, low platelets caused by a genetic mutation, not by auto-antibodies. Getting the right diagnosis is extremely important. Identifying the correct disease helps to avoid unnecessary treatments, receive the most effective care, and manage the risk of related symptoms.
Some types of inherited thrombocytopenia are easy to spot. The platelets can be almost as large as red blood cells or very small, and are often accompanied by additional physical problems. But other cases are very difficult to diagnose or go undiagnosed because here are no specific tests to identify this group of diseases. The platelet size may be normal, several genes may be involved, and not everyone who carries the gene mutations has symptoms, including the parents.
Here are the major questions to ask:
• Have the platelets always been low?
• Do they look different?
• Is there a history of low platelets or treatment for ITP in the family?
• Does the person have other congenital abnormalities?
If some of these answers are ‘yes’ discuss the possibility of inherited thrombocytopenia with the doctor and keep reading about the subject.
This is an evolving and exciting area of research. As scientists continue to explore the genetic make-up of people with suspected inherited thrombocytopenia they are finding more mutations and additional disease categories, but many undiagnosed and misdiagnosed cases remain. Here’s how you can help.
If you or someone you know suspects genetics are a factor in causing low platelets contact Dr. Terry Gernsheimer in Seattle, Washington, Dr. Michele Lambert in Phildadelphia, Pennsylvania, the ITP registry in London, or the MYH9 related diseases registry in Italy.
There are several different genetic problems that are known to result in low platelets and more are being investigated. See the Other Platelet Disorders Page for a list.
(This section is based on Dr. Amy Geddis' presentation at the 2011 ITP Conference)
Family Health History Awareness and Collection
Your family health history is an important component of a primary care visit. It is an independent and significant risk factor for many common, chronic conditions as well as rare genetic disorders, and it is often called the most basic genetic test.
Here are some tools to help record and track your family's health history:
"Does It Run In The Family?" toolkit (from Genetic Alliance)
My Family Health Portrait (from the office of the Surgeon General)