- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:572798)
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:572798)
- Floppy infant (HP:0008947): Floppiness/hypotonia is defined as reduced resistance to passive movement of joints. Physical examination of floppy/hypotonic infants shows head lag, lack of shoulder and elbow muscle contraction on traction response, inability to tighten the shoulder girdle muscles (or slipping through) when held under the axillae, scarf sign (when the arm is pulled to the opposite side, the arm wraps around the neck with the elbow crossing midline), hyperdorsiflexion of the feet, easy apposition of the thumb against the forearm, feet touching the cheek with ease and without discomfort, frog leg position, and inverted U sign on ventral suspension (head, arms, and legs hanging down without elbow or knee flexion and the trunk rounded in a dome shape). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:572798)
- Abnormality of movement (HP:0100022): An abnormality of movement with a neurological basis characterized by changes in coordination and speed of voluntary movements. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:572798)
- Aggressive behavior (HP:0000718): Behavior or an act aimed at harming a person, animal, or physical property (e.g., acts of physical violence; shouting, swearing, and using harsh language; slashing someone's tires). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Cerebellar atrophy (HP:0001272): Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Muscle weakness (HP:0001324): Reduced strength of muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Intrauterine growth retardation (HP:0001511): An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Abnormal speech pattern (HP:0002167): An abnormality in the sound (volume) or cadence (rate) of speech. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Moderate intellectual disability (HP:0002342): Moderate intellectual disability (ID) is defined as a type of ID characterized by moderately sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 35-49. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Limb dystonia (HP:0002451): A type of dystonia (abnormally increased muscular tone causing fixed abnormal postures) that affects muscles of the limbs. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Limb hypertonia (HP:0002509). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Abnormal periventricular white matter morphology (HP:0002518): A structural abnormality of the myelinated axons (white matter) located near the cerebral ventricles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Lactic acidosis (HP:0003128): An abnormal buildup of lactic acid in the body, leading to acidification of the blood and other bodily fluids. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Generalized amyotrophy (HP:0003700): Generalized (diffuse, unlocalized) amyotrophy (muscle atrophy) affecting multiple muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Axial hypotonia (HP:0008936): Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Abnormal circulating enzyme concentration or activity (HP:0012379): Concentration or activity of an enzyme is above or below the limits of normal in the blood circulation. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Cerebral white matter hypoplasia (HP:0012430): Underdevelopment of the cerebral white matter. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- Delayed myelination (HP:0012448): Delayed myelination. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:572798)
- High palate (HP:0000218): Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Thin upper lip vermilion (HP:0000219): Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Hypertelorism (HP:0000316): Interpupillary distance more than 2 SD above the mean (alternatively, the appearance of an increased interpupillary distance or widely spaced eyes). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Low-set ears (HP:0000369): Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Wide nasal bridge (HP:0000431): Increased breadth of the nasal bridge (and with it, the nasal root). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Rod-cone dystrophy (HP:0000510): An inherited retinal disease subtype in which the rod photoreceptors appear to be more severely affected than the cone photoreceptors. Typical presentation is with nyctalopia (due to rod dysfunction) followed by loss of mid-peripheral field of vision, which gradually extends and leaves many patients with a small central island of vision due to the preservation of macular cones. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Exotropia (HP:0000577): A form of strabismus with one or both eyes deviated outward. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Amblyopia (HP:0000646): Reduced visual acuity that is uncorrectable by lenses in the absence of detectable anatomic defects in the eye or visual pathways. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- 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). (ORPHA:572798)
- Dysmetria (HP:0001310): A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Cerebellar vermis hypoplasia (HP:0001320): Underdevelopment of the vermis of cerebellum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Cardiomyopathy (HP:0001638): A myocardial disorder in which the heart muscle is structurally and functionally abnormal, in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed myocardial abnormality. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Thrombocytopenia (HP:0001873): A reduction in the number of circulating thrombocytes. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Neonatal hypoglycemia (HP:0001998). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Profound intellectual disability (HP:0002187): Profound intellectual disability (ID) is defined as a type of ID characterized by profoundly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) below 20. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Dilated fourth ventricle (HP:0002198): An abnormal dilatation of the fourth cerebral ventricle. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Athetosis (HP:0002305): A slow, continuous, involuntary writhing movement that prevents maintenance of a stable posture. Athetosis involves continuous smooth movements that appear random and are not composed of recognizable sub-movements or movement fragments. In contrast to chorea, in athetosis, the same regions of the body are repeatedly involved. Athetosis may worsen with attempts at movement of posture, but athetosis can also occur at rest. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Leukoencephalopathy (HP:0002352): This term describes abnormality of the white matter of the cerebrum resulting from damage to the myelin sheaths of nerve cells. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Hypoplasia of the brainstem (HP:0002365): Underdevelopment of the brainstem. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- 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. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Spastic tetraplegia (HP:0002510): Spastic paralysis affecting all four limbs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Difficulty standing (HP:0003698). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Positional foot deformity (HP:0005656): A foot deformity resulting due to an abnormality affecting the muscle and soft tissue. In contrast if the bones of the foot are affected the term structural foot deformity applies. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Lateral ventricle dilatation (HP:0006956). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Impaired smooth pursuit (HP:0007772): An impairment of the ability to track objects with the ocular smooth pursuit system, a class of rather slow eye movements that minimizes retinal target motion. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Widened subarachnoid space (HP:0012704): An increase in size of the anatomic space between the arachnoid membrane and pia mater. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
- Multifocal seizures (HP:0031165): Seizures that start from several different areas of the brain (i.e., with multiple ictal onset locations). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:572798)
These phenotypes are associated with the disease WARS2-related combined oxidative phosphorylation defect (ORPHA:572798).