Question:  What are the symptoms of Dopa-responsive dystonia ?
Answer: What are the signs and symptoms of Dopa-responsive dystonia? The most common form of dopa-responsive dystonia (DRD) is autosomal dominant DRD (caused by a mutation in the GCH1 gene). This form of DRD is usually characterized by childhood-onset dystonia that may be associated with parkinsonism at an older age. The average age of onset is 6 years, and females are 2-4 times more likely than males to be affected. Symptoms usually begin with lower limb dystonia, resulting in gait problems that can cause stumbling and falling. Symptoms are often worse later in the day, a phenomenon known as diurnal fluctuation. In rare cases, the first symptom may be arm dystonia, tremor of the hands, slowness of movements, or cervical dystonia. This form of DRD usually progresses to affect the whole body, and some people also develop parkinsonism. Depression, anxiety, sleep disturbances and obsessive-compulsive disorder have been reported in some people. Intellectual function is normal. Those with onset at older ages tend to be more mildly affected. Another form of DRD is due to a rare condition called sepiapterin reductase deficiency, which is inherited in an autosomal recessive manner. This form of DRD is also characterized by dystonia with diurnal fluctuations, but also affects motor and cognitive development. Onset usually occurs before the first year of life. Sleep disturbances and psychological symptoms (anxiety, irritability) are common later in childhood. A third form of DRD is autosomal recessive DRD, also called tyrosine hydroxylase deficiency. This form is characterized by a spectrum of symptoms, ranging from those seen in the autosomal dominant form to progressive infantile encephalopathy. Onset is usually in infancy. Intellectual disability, developmental motor delay, and various other features may be present. The Human Phenotype Ontology provides the following list of signs and symptoms for Dopa-responsive dystonia. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Gait disturbance 90% Hypertonia 90% The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.