Phenotypes associated with the disease encephalopathy due to defective mitochondrial and peroxisomal fission 2 (OMIM:617086):
- Hypsarrhythmia (HP:0002521): Hypsarrhythmia is abnormal interictal high amplitude waves and a background of irregular spikes. There is continuous (during wakefulness), high-amplitude (>200 Hz), generalized polymorphic slowing with no organized background and multifocal spikes demonstrated by electroencephalography (EEG). Evidence: PCS. Frequency: 3/3. (PMID:26783368)
- Progressive (HP:0003676): Applies to a disease manifestation that increases in scope or severity over the course of time, i.e., that worsens with age. Evidence: PCS. (PMID:26783368)
- Inability to walk (HP:0002540): Incapability to ambulate. Evidence: TAS. (OMIM:617086)
- Cerebellar atrophy (HP:0001272): Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Evidence: PCS. Frequency: 2/3. (PMID:26783368)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: PCS. Frequency: 3/4. (PMID:26783368)
- Hypotonia (HP:0001252): Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist. Evidence: PCS. Frequency: 3/3. (PMID:26783368)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 4/4. (PMID:26783368)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 4/4. (PMID:26783368)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: PCS. Frequency: 3/3. (PMID:26783368)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: PCS. Frequency: 4/4. (PMID:26783368)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 3/3. (PMID:26783368)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 3/4. (PMID:26783368)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: PCS. Frequency: 3/3. (PMID:26783368)
- Global developmental delay (HP:0001263): A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age. Evidence: TAS. (OMIM:617086)
- Secondary microcephaly (HP:0005484): Head circumference which falls below 2 standard deviations below the mean for age and gender because of insufficient head growth after birth. Evidence: PCS. Frequency: 4/4. (PMID:26783368)
- Epileptic spasm (HP:0011097): A sudden flexion, extension, or mixed extension-flexion of predominantly proximal and truncal muscles that is usually more sustained than a myoclonic movement but not as sustained as a tonic seizure. Limited forms may occur: Grimacing, head nodding, or subtle eye movements. Epileptic spasms frequently occur in clusters. Infantile spasms are the best known form, but spasms can occur at all ages. Evidence: PCS. Frequency: 2/4. (PMID:26783368)
- Death in childhood (HP:0003819): Death in during childhood, defined here as between the ages of 2 and 10 years. Evidence: PCS. Frequency: 1/4. (PMID:26783368)
- Peripheral neuropathy (HP:0009830): Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course. Evidence: TAS. (OMIM:617086)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:22499341)
- Optic atrophy (HP:0000648): Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy. Evidence: TAS. (OMIM:617086)
- Visual impairment (HP:0000505): Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery. Evidence: PCS. Frequency: 3/4. (PMID:26783368)
- Optic disc pallor (HP:0000543): A pale yellow discoloration of the optic disc (the area of the optic nerve head in the retina). The optic disc normally has a pinkish hue with a central yellowish depression. Evidence: PCS. Frequency: 3/4. (PMID:26783368)
- Spasticity (HP:0001257): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: PCS. Frequency: 4/4. (PMID:26783368)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: PCS. Frequency: 1/3. (PMID:26783368)
- External ophthalmoplegia (HP:0000544): Paralysis of the external ocular muscles. Evidence: PCS. Frequency: 3/4. (PMID:26783368)