Phenotypes associated with the disease neurodegeneration with brain iron accumulation 2A (OMIM:256600):
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: IEA. (OMIM:256600)
- Strabismus (HP:0000486): A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error. Evidence: PCS. Frequency: 0/6. (PMID:18799783)
- 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: 1/1. (PMID:18799783)
- 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. (PMID:18799783)
- 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: IEA. (OMIM:256600)
- Short nose (HP:0003196): Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip. Evidence: IEA. (OMIM:256600)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: PCS. Frequency: 4/6. (PMID:18799783)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (OMIM:256600)
- Abnormal pyramidal tract morphology (HP:0002062): Any structural abnormality of the pyramidal tract, whose chief element, the corticospinal tract, is the only direct connection between the brain and the spinal cord. In addition to the corticospinal tract, the pyramidal system includes the corticobulbar, corticomesencephalic, and corticopontine tracts. Evidence: IEA. (OMIM:256600)
- Neurodegeneration (HP:0002180): Progressive loss of neural cells and tissue. Evidence: IEA. (OMIM:256600)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. (PMID:18799783)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 6/6. (PMID:18799783)
- Prominent forehead (HP:0011220): Forward prominence of the entire forehead, due to protrusion of the frontal bone. Evidence: TAS. (OMIM:256600)
- Unsteady gait (HP:0002317). Evidence: IEA. (OMIM:256600)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: IEA. (OMIM:256600)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: IEA. (OMIM:256600)
- EMG: chronic denervation signs (HP:0003444): Evidence of chronic denervation on electromyography. Evidence: PCS. Frequency: 2/6. (PMID:18799783)
- Visual loss (HP:0000572): Loss of visual acuity (implying that vision was better at a certain time point in life). Otherwise the term reduced visual acuity should be used (or a subclass of that). Evidence: IEA. (OMIM:256600)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: PCS. Frequency: 1/1. (PMID:18799783)
- Generalized muscle weakness (HP:0003324): Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature. Evidence: IEA. (OMIM:256600)
- Spastic tetraplegia (HP:0002510): Spastic paralysis affecting all four limbs. Evidence: IEA. (OMIM:256600)
- Delayed speech and language development (HP:0000750): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: PCS. Frequency: 3/6. (PMID:18799783)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: IEA. (OMIM:256600)
- 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: IEA. (OMIM:256600)
- Areflexia (HP:0001284): Absence of neurologic reflexes such as the knee-jerk reaction. Evidence: IEA. (OMIM:256600)
- Gliosis (HP:0002171): Gliosis is the focal proliferation of glial cells in the central nervous system. Evidence: PCS. Frequency: 1/1. (PMID:18799783)
- Iron accumulation in brain (HP:0012675): An abnormal build up of iron (Fe) in brain tissue. Evidence: PCS. Frequency: 7/7. (PMID:16783378;PMID:18799783)
- Reduced social responsiveness (HP:0012760): A reduced ability to participate in the back-and-forth flow of social interaction appropriate to culture and developmental level, which is normally characterized by an influence of the behavior of one person on the behavior of another person. This results in difficulty interacting with others through emotional, physical, or verbal communication. Evidence: PCS. Frequency: 2/6. (PMID:18799783)
- Abnormality of visual evoked potentials (HP:0000649): An anomaly of visually evoked potentials (VEP), which are electrical potentials, initiated by brief visual stimuli, which are recorded from the scalp overlying the visual cortex. Evidence: IEA. (OMIM:256600)
- Abnormal pyramidal sign (HP:0007256): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: TAS. (OMIM:256600)
- 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:16783378)
- Neuronal loss in central nervous system (HP:0002529). Evidence: IEA. (OMIM:256600)
- 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: PCS. Frequency: 4/6. Onset: Childhood onset (HP:0011463). (PMID:18799783)
- Frontal bossing (HP:0002007): Bilateral bulging of the lateral frontal bone prominences with relative sparing of the midline. Evidence: IEA. (OMIM:256600)
- Decreased nerve conduction velocity (HP:0000762): A reduction in the speed at which electrical signals propagate along the axon of a neuron. Evidence: PCS. Frequency: 5/6. (PMID:18799783)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: IEA. (OMIM:256600)