- Severe short stature (HP:0003510): A severe degree of short stature, more than -4 SD from the mean corrected for age and sex. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- 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:29576217)
- Prosopagnosia (HP:0010528): Inability to recognize faces of familiar persons. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Hypermetropia (HP:0000540): An abnormality of refraction characterized by the ability to see objects in the distance clearly, while objects nearby appear blurry. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Dystonia (HP:0001332): An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk. Evidence: PCS. Frequency: 4/4. (PMID:29576217)
- 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: 1/4. (PMID:29576217)
- 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: 2/4. (PMID:29576217)
- 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: 4/4. (PMID:29576217)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 2/4. (PMID:29576217)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Intention tremor (HP:0002080): A type of kinetic tremor that occurs during target directed movement is called intention tremor. That is, an oscillatory cerebellar ataxia that tends to be absent when the limbs are inactive and during the first part of voluntary movement but worsening as the movement continues and greater precision is required (e.g., in touching a target such as the patient's nose or a physician's finger). Evidence: PCS. Frequency: 2/4. (PMID:29576217)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. Frequency: 2/4. (PMID:29576217)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- CNS hypomyelination (HP:0003429): Reduced amount of myelin in the central nervous system resulting from defective myelinogenesis. Evidence: PCS. Frequency: 4/4. (PMID:29576217)
- Leukodystrophy (HP:0002415): Leukodystrophy refers to deterioration of white matter of the brain resulting from degeneration of myelin sheaths in the CNS. Their basic defect is directly related to the synthesis and maintenance of myelin membranes. Symmetric white matter involvement at MRI is a typical finding in patients with leukodystrophies. Evidence: PCS. Frequency: 4/4. (PMID:29576217)
- 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: PCS. Frequency: 1/4. (PMID:29576217)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 3/4. (PMID:29576217)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: PCS. Frequency: 4/4. (PMID:29576217)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: PCS. Frequency: 4/4. (PMID:29576217)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: PCS. Frequency: 4/4. (PMID:29576217)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. (PMID:29576217)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: PCS. Frequency: 2/4. (PMID:29576217)
- 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: PCS. (PMID:29576217)
- Tube feeding (HP:0033454): Feeding problem necessitating food and nutrient delivery via a tube. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Progressive visual loss (HP:0000529): A reduction of previously attained ability to see. Evidence: IEA. (OMIM:617951)
- Sensorineural hearing impairment (HP:0000407): A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- Motor regression (HP:0033044): Loss of previously achieved motor skills, as manifested by loss of developmental motor milestones. Evidence: PCS. Frequency: 3/4. (PMID:29576217)
- Cognitive regression (HP:0034332): Loss of cognitive developmental skills, as manifested by loss of developmental cognitive milestones. Evidence: PCS. Frequency: 4/4. (PMID:29576217)
- Amblyopia (HP:0000646): Reduced visual acuity that is uncorrectable by lenses in the absence of detectable anatomic defects in the eye or visual pathways. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- 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:29576217)
- Abnormal pyramidal sign (HP:0007256): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- 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: 3/4. (PMID:29576217)
- Loss of ambulation (HP:0002505): Inability to walk in a person who previous had the ability to walk. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
- 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: 2/4. (PMID:29576217)
- Athetosis (HP:0002305): A slow, continuous, involuntary writhing movement that prevents maintenance of a stable posture. Athetosis involves continuous smooth movements that appear random and are not composed of recognizable sub-movements or movement fragments. In contrast to chorea, in athetosis, the same regions of the body are repeatedly involved. Athetosis may worsen with attempts at movement of posture, but athetosis can also occur at rest. Evidence: PCS. Frequency: 1/4. (PMID:29576217)
These phenotypes are associated with the disease leukodystrophy, hypomyelinating, 15 (OMIM:617951).