The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
| Signs and Symptoms | Approximate number of patients (when available) |
| Absent speech | Very frequent (present in 80%-99% of cases) |
| Aplasia/Hypoplasia of the cerebellum | Very frequent (present in 80%-99% of cases) |
| Cachexia | Very frequent (present in 80%-99% of cases) |
| Cerebellar atrophy | Very frequent (present in 80%-99% of cases) |
| Developmental regression | Very frequent (present in 80%-99% of cases) |
| Generalized seizures | Very frequent (present in 80%-99% of cases) |
| Intellectual disability, profound | Very frequent (present in 80%-99% of cases) |
| Long face | Very frequent (present in 80%-99% of cases) |
| Macrotia | Very frequent (present in 80%-99% of cases) |
| Narrow face | Very frequent (present in 80%-99% of cases) |
| Neuronal loss in central nervous system | Very frequent (present in 80%-99% of cases) |
| Severe global developmental delay | Very frequent (present in 80%-99% of cases) |
| Strabismus | Very frequent (present in 80%-99% of cases) |
| Thick eyebrow | Very frequent (present in 80%-99% of cases) |
| Truncal ataxia | Very frequent (present in 80%-99% of cases) |
| Adducted thumb | Frequent (present in 30%-79% of cases) |
| Aplasia/Hypoplasia of the corpus callosum | Frequent (present in 30%-79% of cases) |
| Autism | Frequent (present in 30%-79% of cases) |
| Cerebral cortical atrophy | Frequent (present in 30%-79% of cases) |
| Conspicuously happy disposition | Frequent (present in 30%-79% of cases) |
| Dysphagia | Frequent (present in 30%-79% of cases) |
| Dystonia | Frequent (present in 30%-79% of cases) |
| Feeding difficulties in infancy | Frequent (present in 30%-79% of cases) |
| Gait ataxia | Frequent (present in 30%-79% of cases) |
| Gastroesophageal reflux | Frequent (present in 30%-79% of cases) |
| Inappropriate laughter | Frequent (present in 30%-79% of cases) |
| Microcephaly | Frequent (present in 30%-79% of cases) |
| Mutism | Frequent (present in 30%-79% of cases) |
| Nystagmus | Frequent (present in 30%-79% of cases) |
| Ophthalmoplegia | Frequent (present in 30%-79% of cases) |
| Pectus excavatum | Frequent (present in 30%-79% of cases) |
| Ventriculomegaly | Frequent (present in 30%-79% of cases) |
| Abnormality of the nose | Occasional (present in 5%-29% of cases) |
| Death in early adulthood | Occasional (present in 5%-29% of cases) |
| Decreased muscle mass | Occasional (present in 5%-29% of cases) |
| Deeply set eye | Occasional (present in 5%-29% of cases) |
| Joint hyperflexibility | Occasional (present in 5%-29% of cases) |
| Abnormality of the foot | - |
| Bowel incontinence | - |
| Decreased body weight | - |
| Drooling | - |
| Flexion contracture | - |
| Happy demeanor | - |
| Hyperkinesis | - |
| Intellectual disability, progressive | - |
| Intellectual disability, severe | - |
| Long nose | - |
| Loss of ability to walk in first decade | - |
| Muscular hypotonia | - |
| Narrow chest | - |
| Open mouth | - |
| Photosensitive tonic-clonic seizures | - |
| Skeletal muscle atrophy | - |
| Sleep disturbance | - |
| Slender finger | - |
| Urinary incontinence | - |
| X-linked dominant inheritance | - |
Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
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How many people have been diagnosed with Christianson syndrome? See answer
