About This Study

This research study is for people of any age with symptoms consistent with cerebral palsy with no known cause.

The purpose of this study is to understand how many of the people participating in the study have a condition called Aromatic L-amino Acid Decarboxylase (AADC) deficiency, a rare genetic disorder.

Participants receive no-cost diagnostic testing to investigate if their symptoms consistent with cerebral palsy are caused by AADC deficiency. This diagnostic testing, which may include genetic analysis, is conducted through blood testing. This study does not involve any medicines or treatments.

Participants and their families may learn if AADC deficiency may be the cause of their cerebral palsy symptoms.

This research study is being conducted at multiple locations throughout the United States and Europe. To see if there is a study location near you, please click here.

You may email us for additional information by clicking here.

What Is AADC Deficiency?

AADC deficiency is a rare genetic disorder that affects the brain, causes abnormal muscle tone, and affects how a child develops. AADC Deficiency may be the reason for a child's cerebral palsy symptoms.

AADC deficiency is very rare. Because it is so rare, and because the symptoms are similar to symptoms of other diseases, such as cerebral palsy, diagnosis can be difficult.

AADC deficiency is a disorder that interferes with the way the cells in the nervous system talk to each other through substances called neurotransmitters. In AADC deficiency, a genetic mutation (change within a gene) leads to a decrease in the amount of neurotransmitters made.

A person with AADC deficiency may have some or all of the following symptoms. Many of the symptoms of AADC deficiency are similar to cerebral palsy symptoms, and every person is different, so your symptoms or the symptoms of your child may vary.

Some of the most common symptoms of AADC deficiency are:

Low or abnormal muscle tone
Abnormal movements, especially involuntary eye movements*
Delays in your development. A child with AADC deficiency may be late or unable to:
Lift and control his or her head
Crawl, sit, or stand without support
Babble or say words

*People with AADC deficiency often have movement problems. These movement problems include involuntary eye movements (called oculogyric crises). These are moments when your eyes suddenly roll upward involuntarily.

At this time there is no cure for AADC deficiency, however, there are some medicines that doctors use to help treat the symptoms of AADC deficiency.

What to Expect

This research study involves up to two visits to the study center.

At the first visit, before any study procedures start, the study doctor's staff will describe this study in detail. If you wish (or wish for your child) to participate, you must then sign a document called an Informed Consent Form. If your child will be the participant, then they may be asked to sign an Assent Form (depending on their age/ability) to indicate that they understand what will happen, including any potential risks and benefits of participating.

The study doctor will ask questions about the patient's medical history and then, the doctor's staff will take a blood sample.

This blood sample will be sent to a lab for testing to see whether there is a particular sign of AADC deficiency in the blood. If no sign is found, the study doctor will inform you of this, and this study will conclude for that participant.

If a sign of AADC deficiency is found in the first blood sample, genetic testing will be performed, and the study doctor will ask the participant to return to the study center where a second blood sample will then be taken to see if AADC deficiency can be confirmed with a blood test measuring the activity of the AADC enzyme. The study doctor will inform you of the results.

Health Insurance and Participation Costs

Health insurance is not required to participate.

All study visits and tests are provided at no cost.