- Elevated circulating creatine kinase activity (HP:0003236, a Human Phenotype Ontology term): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 1/2. (PMID:28356563)
- Microcephaly (HP:0000252, a Human Phenotype Ontology term): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: IEA. Frequency: Very rare (HP:0040284, a Human Phenotype Ontology term). (OMIM:617613)
- Progressive (HP:0003676, a Human Phenotype Ontology term): Applies to a disease manifestation that increases in scope or severity over the course of time, i.e., that worsens with age. Evidence: IEA. (OMIM:617613)
- Strabismus (HP:0000486, a Human Phenotype Ontology term): 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: 1/2. (PMID:28356563)
- Developmental regression (HP:0002376, a Human Phenotype Ontology term): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: IEA. (OMIM:617613)
- Feeding difficulties (HP:0011968, a Human Phenotype Ontology term): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. Frequency: 2/2. (PMID:28356563)
- 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: PCS. Frequency: 2/2. (PMID:28356563)
- Global developmental delay (HP:0001263, a Human Phenotype Ontology term): 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. Frequency: 2/2. (PMID:28356563)
- Increased circulating lactate concentration (HP:0002151, a Human Phenotype Ontology term): Abnormally increased level of blood lactate (2-hydroxypropanoic acid). Lactate is produced from pyruvate by lactate dehydrogenase during normal metabolism. The terms lactate and lactic acid are often used interchangeably but lactate (the component measured in blood) is strictly a weak base whereas lactic acid is the corresponding acid. Lactic acidosis is often used clinically to describe elevated lactate but should be reserved for cases where there is a corresponding acidosis (pH below 7.35). Evidence: IEA. (OMIM:617613)
- 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: 2/2. (PMID:28356563)
- Pigmentary retinopathy (HP:0000580, a Human Phenotype Ontology term): An abnormality of the retina characterized by pigment deposition. It is typically associated with migration and proliferation of macrophages or retinal pigment epithelial cells into the retina; melanin from these cells causes the pigmentary changes. Pigmentary retinopathy is a common final pathway of many retinal conditions and is often associated with visual loss. Evidence: IEA. Frequency: Very rare (HP:0040284, a Human Phenotype Ontology term). (OMIM:617613)
- Delayed myelination (HP:0012448, a Human Phenotype Ontology term): Delayed myelination. Evidence: IEA. (OMIM:617613)
- 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:28356563)
- Ventriculomegaly (HP:0002119, a Human Phenotype Ontology term): An increase in size of the ventricular system of the brain. Evidence: PCS. Frequency: 2/2. (PMID:28356563)
- Pachygyria (HP:0001302, a Human Phenotype Ontology term): Pachygyria is a malformation of cortical development with abnormally wide gyri with sulci 1,5-3 cm apart and abnormally thick cortex measuring more than 5 mm (radiological definition). See also neuropathological definitions for 2-, 3-, and 4-layered lissencephaly. Evidence: PCS. Frequency: 2/2. (PMID:28356563)
- Growth delay (HP:0001510, a Human Phenotype Ontology term): A deficiency or slowing down of growth pre- and postnatally. Evidence: IEA. (OMIM:617613)
- Leukodystrophy (HP:0002415, a Human Phenotype Ontology term): 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: 2/2. (PMID:28356563)
- Spasticity (HP:0001257, a Human Phenotype Ontology term): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: PCS. Frequency: 2/2. (PMID:28356563)
- Hyperreflexia (HP:0001347, a Human Phenotype Ontology term): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: PCS. Frequency: 2/2. (PMID:28356563)
These phenotypes are associated with the disease multiple mitochondrial dysfunctions syndrome 5 (OMIM:617613, an entry in Online Mendelian Inheritance in Man).