Less common features, include:[4]
Age at time of symptom onset varies from infancy to early adulthood, with onset in infancy to adolescence being most common. Learning disability may begin in childhood. Most people experience a decline in intellectual ability and an increase in muscle weakness and nerve abnormalities over time. As the condition progresses, some people require wheelchair assistance (often 10 to 20 years after symptom onset).[4][2]
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) |
| Aplasia/Hypoplasia of the corpus callosum | 90% |
| Cerebral cortical atrophy | 90% |
| Gait disturbance | 90% |
| Incoordination | 90% |
| Neurological speech impairment | 90% |
| Seizures | 90% |
| Ventriculomegaly | 90% |
| Abnormality of the periventricular white matter | - |
| Adult onset | - |
| Agenesis of corpus callosum | - |
| Ankle clonus | - |
| Ataxia | - |
| Autosomal recessive inheritance | - |
| Babinski sign | - |
| Childhood onset | - |
| Decreased number of peripheral myelinated nerve fibers | - |
| Degeneration of the lateral corticospinal tracts | - |
| Distal peripheral sensory neuropathy | - |
| Dysarthria | - |
| Dysphagia | - |
| Gaze-evoked nystagmus | - |
| Hyperreflexia | - |
| Hypoplasia of the corpus callosum | - |
| Impaired vibration sensation in the lower limbs | - |
| Intellectual disability | - |
| Knee clonus | - |
| Lower limb muscle weakness | - |
| Lower limb spasticity | - |
| Macular degeneration | - |
| Mental deterioration | - |
| Motor polyneuropathy | - |
| Obesity | - |
| Pes cavus | - |
| Progressive | - |
| Retinal degeneration | - |
| Sensory neuropathy | - |
| Spastic gait | - |
| Spastic paraplegia | - |
| Specific learning disability | - |
| Thenar muscle atrophy | - |
| Tip-toe gait | - |
| Urinary bladder sphincter dysfunction | - |
| Urinary incontinence | - |
| Urinary urgency | - |
| Visual impairment | - |
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. Suggest an organization to add.
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.
Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question
What is this exactly and how does it effect someone? See answer
