- Hyperactive deep tendon reflexes (HP:0006801, a Human Phenotype Ontology term). Evidence: PCS. (OMIM:245200)
- Hypertonia (HP:0001276, a Human Phenotype Ontology term): A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move. Evidence: PCS. (PMID:20886637)
- Hearing impairment (HP:0000365, a Human Phenotype Ontology term): A decreased magnitude of the sensory perception of sound. Evidence: PCS. (OMIM:245200)
- Seizure (HP:0001250, a Human Phenotype Ontology term): 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: IEA. (OMIM:245200)
- Hypotonia (HP:0001252, a Human Phenotype Ontology term): 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. (PMID:20886637)
- Infantile onset (HP:0003593, a Human Phenotype Ontology term): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 25/30. (PMID:20886637)
- Neurodegeneration (HP:0002180, a Human Phenotype Ontology term): Progressive loss of neural cells and tissue. Evidence: IEA. (OMIM:245200)
- Failure to thrive (HP:0001508, a Human Phenotype Ontology term): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: IEA. (OMIM:245200)
- Nystagmus (HP:0000639, a Human Phenotype Ontology term): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. (PMID:20886637)
- Sensorimotor neuropathy (HP:0007141, a Human Phenotype Ontology term). Evidence: IEA. (OMIM:245200)
- Childhood onset (HP:0011463, a Human Phenotype Ontology term): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 4/30. (PMID:20886637)
- Young adult onset (HP:0011462, a Human Phenotype Ontology term): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. Frequency: 1/30. (PMID:20886637)
- Reduced tissue galactocerebrosidase activity (HP:0034322, a Human Phenotype Ontology term): Concentration or activity of galactocerebrosidase (EC 3.2.1.46) below the lower limit of normal. This enzyme can be measured in multiple tissues including leukocytes and cultured fibroblasts. Evidence: PCS. Frequency: 29/29. (PMID:20886637)
- Blindness (HP:0000618, a Human Phenotype Ontology term): Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation. Evidence: IEA. (OMIM:245200)
- Hydrocephalus (HP:0000238, a Human Phenotype Ontology term): Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation. Evidence: IEA. (OMIM:245200)
- CNS demyelination (HP:0007305, a Human Phenotype Ontology term): A loss of myelin from nerve fibers in the central nervous system. Evidence: PCS. Frequency: 5/22. (PMID:20886637)
- Motor deterioration (HP:0002333, a Human Phenotype Ontology term): Loss of previously present motor (i.e., movement) abilities. Evidence: IEA. (OMIM:245200)
- Axial hypotonia (HP:0008936, a Human Phenotype Ontology term): Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk. Evidence: PCS. Frequency: 23/30. (PMID:20886637)
- EEG abnormality (HP:0002353, a Human Phenotype Ontology term): Abnormality observed by electroencephalogram (EEG), which is used to record of the brain's spontaneous electrical activity from multiple electrodes placed on the scalp. Evidence: IEA. (OMIM:245200)
- Developmental regression (HP:0002376, a Human Phenotype Ontology term): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: PCS. Frequency: 12/30. (PMID:20886637)
- Vomiting (HP:0002013, a Human Phenotype Ontology term): Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions. Evidence: IEA. (OMIM:245200)
- Abnormal flash visual evoked potentials (HP:0007928, a Human Phenotype Ontology term): Anomaly of the visual evoked potentials elicited by a flash stimulus, generally a flash of light subtending an angle of at least 20 degrees of the visual field and presented in a dimly lit room. Evidence: IEA. (OMIM:245200)
- Decerebrate rigidity (HP:0025013, a Human Phenotype Ontology term): A type of rigidity that is manifested by an exaggerated extensor posture of all extremities. Evidence: TAS. (OMIM:245200)
- Progressive spasticity (HP:0002191, a Human Phenotype Ontology term): Spasticity that increases in degree with time. Evidence: PCS. Frequency: 30/30. (PMID:20886637)
- Peripheral demyelination (HP:0011096, a Human Phenotype Ontology term): A loss of myelin from the internode regions along myelinated nerve fibers of the peripheral nervous system. Evidence: PCS. (OMIM:245200)
- Diffuse cerebral atrophy (HP:0002506, a Human Phenotype Ontology term): Diffuse unlocalised atrophy affecting the cerebrum. Evidence: IEA. (OMIM:245200)
- Autosomal recessive inheritance (HP:0000007, a Human Phenotype Ontology term): 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:8297359)
- Recurrent fever (HP:0001954, a Human Phenotype Ontology term): Periodic (episodic or recurrent) bouts of fever. Evidence: TAS. (OMIM:245200)
- Increased CSF protein concentration (HP:0002922, a Human Phenotype Ontology term): Increased concentration of protein in the cerebrospinal fluid. Evidence: IEA. (OMIM:245200)
- Optic atrophy (HP:0000648, a Human Phenotype Ontology term): 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: IEA. (OMIM:245200)
- Autoimmune thrombocytopenia (HP:0001973, a Human Phenotype Ontology term): The presence of thrombocytopenia in combination with detection of antiplatelet antibodies. Evidence: IEA. (OMIM:245200)
- Decreased nerve conduction velocity (HP:0000762, a Human Phenotype Ontology term): A reduction in the speed at which electrical signals propagate along the axon of a neuron. Evidence: IEA. (OMIM:245200)
These phenotypes are associated with the disease Krabbe disease (OMIM:245200, an entry in Online Mendelian Inheritance in Man).