What are the signs and symptoms of Aromatic L-amino acid decarboxylase deficiency? Symptoms, which typically present during the first year of life, include severe developmental delay, weak muscle tone (hypotonia), muscle stiffness, difficulty moving, and involuntary writhing movements of the limbs (athetosis). This condition may also cause infants to lack energy, feed poorly, startle easily, and have sleep disturbances. Many people with AADC deficiency exprience episodes called oculogyric crises (also called "spells" or "attacks"), which are characterized by abnormal rotation of the eyeballs, extreme irritability and agitation, pain, muscle spasms, and uncontrolled movements of the head and neck.. These episodes can last for many hours and can be times of extreme concern for caregivers and family members. AADC deficiency may also affect the autonomic nervous system, which controls involuntary body processes like regulation of blood pressure and body temperature. Autonomic symptoms may include droopy eye lids (ptosis), constriction of the pupils of the eyes (miosis), inappropriate or impaired sweating, nasal congestion, drooling, reduced ability to control body temperature, low blood pressure (hypotension), gastroesophageal reflux, low blood sugar (hypoglycemia), fainting (syncope), and cardiac arrest.   The signs and symptoms of AADC deficiency tend to worsen late in the day or when the individual is tired, and improve after sleep. The Human Phenotype Ontology provides the following list of signs and symptoms for Aromatic L-amino acid decarboxylase deficiency. 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) Abnormality of the face - Autosomal recessive inheritance - Babinski sign - Choreoathetosis - Constipation - Decreased CSF homovanillic acid (HVA) - Diarrhea - Emotional lability - Feeding difficulties in infancy - Gastroesophageal reflux - Hyperhidrosis - Hyperreflexia - Hypotension - Infantile onset - Intermittent hypothermia - Irritability - Limb dystonia - Limb hypertonia - Miosis - Muscular hypotonia of the trunk - Myoclonus - Ptosis - Sleep disturbance - Temperature instability - 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.