- Lethargy (HP:0001254): A state of fatigue, either physical or mental slowness and sluggishness, with difficulties in initiating or performing simple tasks. Distinguished from apathy which implies indifference and a lack of desire or interest in the task. A person with lethargy may have the desire, but not the energy to engage in personal or socially relevant tasks. Evidence: PCS. Frequency: 6/6. (PMID:33457206;PMID:24498631)
- Hepatic steatosis (HP:0001397): Steatosis is a term used to denote lipid accumulation within hepatocytes. Evidence: PCS. Frequency: 2/2. (PMID:24498631)
- Elevated circulating creatine kinase activity (HP:0003236): The activity of creatine kinase in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 3/3. (PMID:24498631)
- Aminoaciduria (HP:0003355): An increased concentration of an amino acid in the urine. Evidence: PCS. Frequency: 2/2. (PMID:33457206)
- 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: 2/5. (PMID:33457206;PMID:24498631)
- Renal insufficiency (HP:0000083): A reduction in the level of performance of the kidneys in areas of function comprising the concentration of urine, removal of wastes, the maintenance of electrolyte balance, homeostasis of blood pressure, and calcium metabolism. Evidence: PCS. Frequency: 2/3. (PMID:24498631)
- 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: 6/6. (PMID:33457206;PMID:24498631)
- Elevated circulating alanine aminotransferase concentration (HP:0031964): An abnormally high concentration in the circulation of alanine aminotransferase (ALT). Evidence: PCS. Frequency: 3/3. (PMID:33457206)
- Hypoglycemia (HP:0001943): A decreased concentration of glucose in the blood. Evidence: PCS. Frequency: 4/6. (PMID:33457206;PMID:24498631)
- Respiratory failure (HP:0002878): A severe form of respiratory insufficiency characterized by inadequate gas exchange such that the levels of oxygen or carbon dioxide cannot be maintained within normal limits. Evidence: PCS. Frequency: 4/6. (PMID:33457206;PMID:24498631)
- Decreased activity of mitochondrial complex II (HP:0008314): A reduction in the activity of the mitochondrial respiratory chain complex II, which is part of the electron transport chain in mitochondria. Evidence: PCS. (PMID:24498631)
- Lacticaciduria (HP:0003648): An increased concentration of lactic acid in the urine. Evidence: PCS. Frequency: 2/3. (PMID:33457206)
- Death in infancy (HP:0001522): Death within the first 24 months of life. Evidence: PCS. Frequency: 2/3. (PMID:24498631)
- Metabolic acidosis (HP:0001942): Metabolic acidosis (MA) is characterized by a fall in blood pH due to a reduction of serum bicarbonate concentration. This can occur as a result of either the accumulation of acids (high anion gap MA) or the loss of bicarbonate from the gastrointestinal tract or the kidney (hyperchloremic MA). By definition, MA is not due to a respirary cause. Evidence: PCS. Frequency: 3/3. (PMID:24498631)
- Anorexia (HP:0002039): Lack of desire to eat (loss of appetite). Evidence: PCS. Frequency: 3/3. (PMID:24498631)
- Hyperalaninemia (HP:0003348): An increased concentration of alanine in the blood. Evidence: PCS. Frequency: 2/3. (PMID:33457206)
- Elevated circulating aspartate aminotransferase concentration (HP:0031956): The concentration of aspartate aminotransferase (AST) in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 3/3. (PMID:24498631)
- Hyperamylasemia (HP:0410288): The concentration of amylase in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 1/5. (PMID:33457206;PMID:24498631)
- Disseminated intravascular coagulation (HP:0005521): Disseminated intravascular coagulation is characterized by the widespread activation of coagulation, which results in the intravascular formation of fibrin and ultimately thrombotic occlusion of small and midsize vessels. Evidence: PCS. Frequency: 4/5. (PMID:33457206;PMID:24498631)
- Decreased activity of mitochondrial complex III (HP:0011924): A reduction in the activity of the mitochondrial respiratory chain complex III, which is part of the electron transport chain in mitochondria. Evidence: PCS. (PMID:24498631)
- Hyperglycinemia (HP:0002154): An elevated concentration of glycine in the blood. Evidence: PCS. Frequency: 3/3. (PMID:33457206)
- Increased circulating lactate concentration (HP:0002151): 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: PCS. Frequency: 6/6. (PMID:33457206;PMID:24498631)
- Hypertrophic cardiomyopathy (HP:0001639): Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality. Evidence: PCS. Frequency: 1/3. (PMID:33457206)
- 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:24498631)
- Adrenal insufficiency (HP:0000846): Insufficient production of steroid hormones (primarily cortisol) by the adrenal glands. Evidence: PCS. Frequency: 1/3. (PMID:33457206)
- Pancreatitis (HP:0001733): The presence of inflammation in the pancreas. Evidence: PCS. Frequency: 1/3. (PMID:24498631)
These phenotypes are associated with the disease combined oxidative phosphorylation deficiency 52 (OMIM:619386).