Phenotypes associated with the disease multiple mitochondrial dysfunctions syndrome 2 (OMIM:614299):
- Poor head control (HP:0002421): Difficulty to maintain correct position of the head while standing or sitting. Infant head lag is observed when the head seems to flop around or lags posteriorly behind the trunk. Several articles have maintained that head lag should be absent by age 3 to 4 months. Evidence: TAS. (OMIM:614299)
- 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: 1/1. (PMID:21944046)
- 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: 1/1. (PMID:21944046)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:614299)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (OMIM:614299)
- Decreased activity of mitochondrial respiratory chain (HP:0008972): Decreased activity of the mitochondrial respiratory chain. Evidence: TAS. (OMIM:614299)
- Hyperhidrosis (HP:0000975): Abnormal excessive perspiration (sweating) despite the lack of appropriate stimuli like hot and humid weather. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- 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: TAS. (OMIM:614299)
- 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. Frequency: 1/1. (PMID:21944046)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: TAS. (OMIM:614299)
- Death in infancy (HP:0001522): Death within the first 24 months of life. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- Leukodystrophy (HP:0002415): 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: TAS. (OMIM:614299)
- 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: 1/1. (PMID:21944046)
- Dilated cardiomyopathy (HP:0001644): Dilated cardiomyopathy (DCM) is defined by the presence of left ventricular dilatation and left ventricular systolic dysfunction in the absence of abnormal loading conditions (hypertension, valve disease) or coronary artery disease sufficient to cause global systolic impairment. Right ventricular dilation and dysfunction may be present but are not necessary for the diagnosis. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- Vomiting (HP:0002013): Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions. Evidence: TAS. (OMIM:614299)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: IEA. (OMIM:614299)
- Respiratory distress (HP:0002098): Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- 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. Frequency: 1/1. (PMID:21944046)
- Hyperglycinemia (HP:0002154): An elevated concentration of glycine in the blood. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- 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: 1/1. (PMID:21944046)
- Respiratory insufficiency (HP:0002093). Evidence: TAS. (OMIM:614299)
- Abnormality of extrapyramidal motor function (HP:0002071): A neurological condition related to lesions of the basal ganglia leading to typical abnormalities including akinesia (inability to initiate changes in activity and perform volitional movements rapidly and easily), muscular rigidity (continuous contraction of muscles with constant resistance to passive movement), chorea (widespread arrhythmic movements of a forcible, rapid, jerky, and restless nature), athetosis (inability to sustain the muscles of the fingers, toes, or other group of muscles in a fixed position), and akathisia (inability to remain motionless). Evidence: TAS. (OMIM:614299)
- 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. Frequency: 1/1. (PMID:21944046)
- Reduced tissue glycine cleavage enzyme activity (HP:6000829): Concentration or activity of the glycine cleavage enzyme below the lower limit of normal. This enzyme can be measured in multiple tissues including leukocytes and cultured fibroblasts. Evidence: PCS. (PMID:24334290)
- Increased CSF glycine concentration (HP:0500230): Abnormally increased levels of glycine in cerebrospinal fluid. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- Decreased activity of the pyruvate dehydrogenase complex (HP:0002928). Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- 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: TAS. (OMIM:614299)
- 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:21944046)
- Visual impairment (HP:0000505): Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:614299)
- Optic atrophy (HP:0000648): 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: TAS. Frequency: Occasional (HP:0040283). (OMIM:614299)
- Epileptic encephalopathy (HP:0200134): A condition in which epileptiform abnormalities are believed to contribute to the progressive disturbance in cerebral function. Epileptic encephalaopathy is characterized by (1) electrographic EEG paroxysmal activity that is often aggressive, (2) seizures that are usually multiform and intractable, (3) cognitive, behavioral and neurological deficits that may be relentless, and (4) sometimes early death. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- Tachypnea (HP:0002789): Very rapid breathing. Evidence: PCS. Frequency: 1/1. (PMID:21944046)
- 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: TAS. (OMIM:614299)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:614299)