What are the symptoms of Tetrahydrobiopterin deficiency ?
What are the signs and symptoms of Tetrahydrobiopterin deficiency? Infants with tetrahydrobiopterin (BH4) deficiency typically appear normal and healthy at birth. Neurological signs and symptoms usually become apparent over time, and can range from mild to severe. These may include abnormal muscle tone; poor sucking and coordination; seizures; and delayed motor development. Other manifestations may include decreased spontaneous movements and difficulty swallowing. Without early and appropriate treatment, signs and symptoms progress and affected individuals may experience irreversible intellectual disability, behavioral problems, an inability to control body temperature, and even death in severe cases. The Human Phenotype Ontology provides the following list of signs and symptoms for Tetrahydrobiopterin 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) Cognitive impairment 90% Microcephaly 90% Abnormality of eye movement - Ataxia - Autosomal recessive inheritance - Bradykinesia - Cerebral calcification - Choreoathetosis - Dysphagia - Dystonia - Episodic fever - Excessive salivation - Hyperkinesis - Hyperphenylalaninemia - Hyperreflexia - Hypertonia - Infantile onset - Intellectual disability - Intellectual disability, progressive - Irritability - Lethargy - Limb hypertonia - Motor delay - Muscular hypotonia - Muscular hypotonia of the trunk - Myoclonus - Parkinsonism - Poor suck - Progressive neurologic deterioration - Rigidity - Seizures - Severe muscular hypotonia - Small for gestational age - Somnolence - Transient hyperphenylalaninemia - Tremor - Variable expressivity - 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.