THE CHALLENGE OF A CORRECT DIAGNOSIS
Although symptoms are often seen when the person is still an infant, an accurate diagnosis may take a long time. AADC deficiency is rare, and many of its symptoms may overlap with those of other disorders, so there may be a delay in diagnosis.
Symptoms of AADC deficiency may look like other conditions:
| Symptoms of AADC deficiency | Other conditions |
|---|---|
| Oculogyric crises | |
| Rigidity (stiffness) Developmental impairment |
|
| Involuntary muscle contractions Rigidity Delays in development |
|
| Delays in development | Behavioral disorders/autism |
| Low muscle tone Delays in development |
|
| Low muscle tone Involuntary muscle contractions Motor delays |
*Parkinsonism is a general term that refers to a group of neurological disorders that cause movement problems similar to those seen in Parkinson’s disease.
Dopamine deficiency in juvenile parkinsonism and AADC deficiency results in a similar presentation of symptoms. However AADC deficiency, unlike juvenile parkinsonism, involves only a single gene mutation, is nonprogressive, and presents the signs and symptoms during infancy.
When AADC deficiency is not diagnosed right away or is never correctly diagnosed, treatment and proper management of this condition are delayed.
“Knowing what the diagnosis is and knowing what the prognosis is can help get the family prepared.”
Other signs and symptoms to help identify AADC deficiency
Involuntary eye movements called oculogyric crises
During these episodes, a child’s eyes will suddenly roll upward, without control; they can last anywhere from a few seconds to hours and can happen several times a day or several times a week. When these episodes occur, it can look as though the child is having a seizure
Normal brain scans
Including normal CT, MRI, and EEG
Multiple symptoms associated with bodily functions (autonomic symptoms)
Such as the body being unable to control its temperature (temperature instability), excessive sweating, a stuffy nose, and changes in blood pressure
Symptoms may become worse or more noticeable
Later in the day and improve with sleep
If your child is showing 1 or a combination of these signs and symptoms, you may want to talk to your child’s doctor about screening for AADC deficiency.
CT=computed tomography; EEG=electroencephalogram; MRI=magnetic resonance imaging.
“Daria had these attacks, or oculogyric spasms, which [we now know] are a characteristic of AADC deficiency—it put her in a completely different state.”
What are oculogyric crises?
An expert discusses what oculogyric crises look like.
