- Encephalopathy (HP:0001298): Encephalopathy is a term that means brain disease, damage, or malfunction. In general, encephalopathy is manifested by an altered mental state. Evidence: IEA. (OMIM:251880)
- Hepatic steatosis (HP:0001397): Steatosis is a term used to denote lipid accumulation within hepatocytes. Evidence: IEA. (OMIM:251880)
- Hepatic failure (HP:0001399). Evidence: PCS. Frequency: 19/19. (PMID:11687800)
- Hypothermia (HP:0002045): Reduced body temperature due to failed thermoregulation. Evidence: IEA. (OMIM:251880)
- 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: IEA. (OMIM:251880)
- Polyneuropathy (HP:0001271): A generalized disorder of peripheral nerves. Evidence: IEA. (OMIM:251880)
- 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: IEA. (OMIM:251880)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: IEA. (OMIM:251880)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. (PMID:11687800)
- Hypoalbuminemia (HP:0003073): The concentration of albumin in the blood circulation is below the lower limit of normal. Evidence: IEA. (OMIM:251880)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: 19/19. (PMID:11687800)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: IEA. (OMIM:251880)
- Portal hypertension (HP:0001409): Increased pressure in the portal vein. Evidence: IEA. (OMIM:251880)
- Periportal fibrosis (HP:0001405): The presence of fibrosis affecting the interlobular stroma of liver. Evidence: IEA. (OMIM:251880)
- Elevated circulating alpha-fetoprotein concentration (HP:0006254): The concentration of alpha-fetoprotein in the blood circulation is above the upper limit of normal. Evidence: PCS. Frequency: 19/19. (PMID:11687800)
- Feeding difficulties in infancy (HP:0008872): Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention. Evidence: IEA. (OMIM:251880)
- Hepatocellular necrosis (HP:0001404). Evidence: IEA. (OMIM:251880)
- Hypoglycemia (HP:0001943): A decreased concentration of glucose in the blood. Evidence: IEA. (OMIM:251880)
- Elevated circulating hepatic transaminase concentration (HP:0002910): Elevations of the levels of SGOT and SGPT in the serum. SGOT (serum glutamic oxaloacetic transaminase) and SGPT (serum glutamic pyruvic transaminase) are transaminases primarily found in the liver and heart and are released into the bloodstream as the result of liver or heart damage. SGOT and SGPT are used clinically mainly as markers of liver damage. Evidence: IEA. (OMIM:251880)
- Jaundice (HP:0000952): Yellow pigmentation of the skin due to bilirubin, which in turn is the result of increased bilirubin concentration in the bloodstream. Evidence: IEA. (OMIM:251880)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: IEA. (OMIM:251880)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: IEA. (OMIM:251880)
- Lactic acidosis (HP:0003128): An abnormal buildup of lactic acid in the body, leading to acidification of the blood and other bodily fluids. Evidence: PCS. Frequency: 19/19. (PMID:11687800)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. (PMID:11687800)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: IEA. (OMIM:251880)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: IEA. (OMIM:251880)
- Ascites (HP:0001541): Accumulation of fluid in the peritoneal cavity (between the layers of the peritoneum that lines the abdomen). Evidence: IEA. (OMIM:251880)
- Vomiting (HP:0002013): Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions. Evidence: IEA. (OMIM:251880)
- 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:11687800)
- Decreased activity of mitochondrial complex I (HP:0011923): A reduction in the activity of the mitochondrial respiratory chain complex I, which is part of the electron transport chain in mitochondria. Evidence: PCS. (PMID:11687800)
- Generalized aminoaciduria (HP:0002909): An increased concentration of all types of amino acid in the urine. Evidence: IEA. (OMIM:251880)
- Depletion of mitochondrial DNA in liver (HP:0006581): An abnormal reduction in the number of mitochondria in hepatocytes. Evidence: PCS. Frequency: 5/5. (PMID:11687800)
- Hyperbilirubinemia (HP:0002904): An increased amount of bilirubin in the blood. Evidence: IEA. (OMIM:251880)
- 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:11687800)
- Abnormal conjugate eye movement (HP:0000549): Any deviation from the normal motor coordination of the eyes that allows for bilateral fixation on a single object. Evidence: IEA. (OMIM:251880)
- Decreased activity of mitochondrial complex IV (HP:0008347): A reduction in the activity of the mitochondrial respiratory chain complex IV, which is part of the electron transport chain in mitochondria. Evidence: PCS. (PMID:11687800)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: TAS. (OMIM:251880)
- Thrombocytopenia (HP:0001873): A reduction in the number of circulating thrombocytes. Evidence: IEA. (OMIM:251880)
- Micronodular cirrhosis (HP:0001413): A type of cirrhosis characterized by the presence of small regenerative nodules. Evidence: IEA. (OMIM:251880)
These phenotypes are associated with the disease mitochondrial DNA depletion syndrome 3 (hepatocerebral type) (OMIM:251880).