- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 2/10. (PMID:34038740)
- Dysplastic corpus callosum (HP:0006989): Dysplasia and dysgenesis of the corpus callosum are nonspecific descriptions that imply defective development of the corpus callosum. The term dysplasia is applied when the morphology of the corpus callosum is altered as a congenital trait. For instance, the corpus callosum may be hump-shaped, kinked, or a striped corpus callosum that lacks an anatomically distinct genu and splenium. Evidence: PCS. Frequency: 8/10. (PMID:34038740)
- Hypochromic microcytic anemia (HP:0004840): A type of anemia characterized by an abnormally low concentration of hemoglobin in the erythrocytes and lower than normal size of the erythrocytes. Evidence: PCS. Frequency: 4/4. (PMID:34038740)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: PCS. Frequency: 7/7. (PMID:34038740)
- 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: 11/11. (PMID:34038740)
- 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. Frequency: 12/12. (PMID:34038740)
- 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: 9/11. (PMID:34038740)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 6/10. (PMID:34038740)
- 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: 9/10. (PMID:34038740)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: PCS. Frequency: 2/8. (PMID:34038740)
- Septic arthritis (HP:0003095). Evidence: PCS. Frequency: 2/9. (PMID:34038740)
- Abdominal distention (HP:0003270): Distention of the abdomen. Evidence: PCS. Frequency: 4/8. (PMID:34038740)
- Elevated circulating C-reactive protein concentration (HP:0011227): The concentration of C-reactive protein in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 5/8. (PMID:34038740)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: 9/9. (PMID:34038740)
- Death in childhood (HP:0003819): Death in during childhood, defined here as between the ages of 2 and 10 years. Evidence: PCS. Frequency: 2/12. (PMID:34038740)
- 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:34038740)
- Recurrent fever (HP:0001954): Periodic (episodic or recurrent) bouts of fever. Evidence: PCS. Frequency: 8/9. (PMID:34038740)
- CNS hypomyelination (HP:0003429): Reduced amount of myelin in the central nervous system resulting from defective myelinogenesis. Evidence: PCS. Frequency: 6/7. (PMID:34038740)
- Death in infancy (HP:0001522): Death within the first 24 months of life. Evidence: PCS. Frequency: 7/12. (PMID:34038740)
- 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: 4/7. (PMID:34038740)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 2/10. (PMID:34038740)
- Arthritis (HP:0001369): Inflammation of a joint. Evidence: PCS. Frequency: 3/9. (PMID:34038740)
- Osteomyelitis (HP:0002754): Osteomyelitis is an inflammatory process accompanied by bone destruction and caused by an infecting microorganism. Evidence: PCS. Frequency: 2/8. (PMID:34038740)
- Generalized amyotrophy (HP:0003700): Generalized (diffuse, unlocalized) amyotrophy (muscle atrophy) affecting multiple muscles. Evidence: PCS. Frequency: 8/8. (PMID:34038740)
These phenotypes are associated with the disease combined oxidative phosphorylation deficiency 53 (OMIM:619423).