- Epicanthus (HP:0000286, a Human Phenotype Ontology term): A fold of skin starting above the medial aspect of the upper eyelid and arching downward to cover, pass in front of and lateral to the medial canthus. Evidence: IEA. (OMIM:213300)
- Poor head control (HP:0002421, a Human Phenotype Ontology term): 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: PCS. Frequency: 1/1. (PMID:29230161)
- Strabismus (HP:0000486, a Human Phenotype Ontology term): A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error. Evidence: PCS. Frequency: 1/1. (PMID:29230161)
- Protruding tongue (HP:0010808, a Human Phenotype Ontology term): Tongue extending beyond the alveolar ridges or teeth at rest. Evidence: TAS. (OMIM:213300)
- Hypotonia (HP:0001252, a Human Phenotype Ontology term): 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:213300)
- Ataxia (HP:0001251, a Human Phenotype Ontology term): 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: PCS. Frequency: 8/8. (PMID:29230161;PMID:19668216)
- Generalized hypotonia (HP:0001290, a Human Phenotype Ontology term): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 8/8. (PMID:29230161;PMID:19668216)
- Elongated superior cerebellar peduncle (HP:0011933, a Human Phenotype Ontology term): Increased length of the superior cerebellar peduncle. Evidence: TAS. (OMIM:213300)
- Aggressive behavior (HP:0000718, a Human Phenotype Ontology term): 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: IEA. (OMIM:213300)
- Prominent forehead (HP:0011220, a Human Phenotype Ontology term): Forward prominence of the entire forehead, due to protrusion of the frontal bone. Evidence: PCS. (OMIM:213300)
- Molar tooth sign on MRI (HP:0002419, a Human Phenotype Ontology term): An abnormal appearance of the midbrain in axial magnetic resonance imaging in which the elongated superior cerebellar peduncles give the midbrain an appearance reminiscent of a molar or wisdom tooth. Evidence: PCS. Frequency: 7/7. (PMID:19668216)
- Delayed ability to sit (HP:0025336, a Human Phenotype Ontology term): A failure to achieve the ability to sit at an appropriate developmental stage. Most children sit with support at 6 months of age and sit steadily without support at 9 months of age. Evidence: PCS. Frequency: 1/1. (PMID:29230161)
- Hyperactivity (HP:0000752, a Human Phenotype Ontology term): Hyperactivity is a condition characterized by constant and unusually high levels of activity, even in situations where it is deemed inappropriate. Evidence: IEA. (OMIM:213300)
- Macroglossia (HP:0000158, a Human Phenotype Ontology term): Increased length and width of the tongue. Evidence: IEA. (OMIM:213300)
- Agenesis of cerebellar vermis (HP:0002335, a Human Phenotype Ontology term): Congenital absence of the vermis of cerebellum. Evidence: TAS. (OMIM:213300)
- Intellectual disability (HP:0001249, a Human Phenotype Ontology term): 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: PCS. Frequency: 6/6. (PMID:19668216)
- Retinal dystrophy (HP:0000556, a Human Phenotype Ontology term): Retinal dystrophy is an abnormality of the retina associated with a hereditary process. Retinal dystrophies are defined by their predominantly monogenic inheritance and they are frequently associated with loss or dysfunction of photoreceptor cells as a primary or secondary event. Evidence: IEA. (OMIM:213300)
- Highly arched eyebrow (HP:0002553, a Human Phenotype Ontology term): Increased height of the central portion of the eyebrow, forming a crescent, semicircular, or inverted U shape. Evidence: PCS. (OMIM:213300)
- Microcephaly (HP:0000252, a Human Phenotype Ontology term): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 1/7. (PMID:19668216)
- Central apnea (HP:0002871, a Human Phenotype Ontology term): Apnea resulting from depression of the respiratory centers in the medulla oblongata. There is a lack of respiratory effort rather than obstruction of airflow. Evidence: IEA. (OMIM:213300)
- Abnormal saccadic eye movements (HP:0000570, a Human Phenotype Ontology term): An abnormality of eye movement characterized by impairment of fast (saccadic) eye movements. Evidence: IEA. (OMIM:213300)
- Dysgenesis of the cerebellar vermis (HP:0002195, a Human Phenotype Ontology term): Defective development of the vermis of cerebellum. Evidence: TAS. (OMIM:213300)
- Global developmental delay (HP:0001263, a Human Phenotype Ontology term): 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: 8/8. (PMID:29230161;PMID:19668216)
- Neonatal breathing dysregulation (HP:0002790, a Human Phenotype Ontology term). Evidence: IEA. (OMIM:213300)
- Occipital myelomeningocele (HP:0007271, a Human Phenotype Ontology term). Evidence: PCS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (OMIM:213300)
- Brainstem dysplasia (HP:0002508, a Human Phenotype Ontology term): A developmental structural anomaly of the stalk-like part of the brain that comprises the midbrain (aka mesencephalon), the pons (aka pons Varolii), and the medulla oblongata, and connects the cerebral hemispheres with the cervical spinal cord. Evidence: IEA. (OMIM:213300)
- Autosomal recessive inheritance (HP:0000007, a Human Phenotype Ontology term): 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:19668216)
- Chorioretinal coloboma (HP:0000567, a Human Phenotype Ontology term): Absence of a region of the retina, retinal pigment epithelium, and choroid. Evidence: IEA. (OMIM:213300)
- Low-set ears (HP:0000369, a Human Phenotype Ontology term): 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: PCS. Frequency: 1/1. (PMID:29230161)
- Anteverted nares (HP:0000463, a Human Phenotype Ontology term): Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip). Evidence: IEA. (OMIM:213300)
- Hypoplasia of the brainstem (HP:0002365, a Human Phenotype Ontology term): Underdevelopment of the brainstem. Evidence: IEA. (OMIM:213300)
- Hepatic fibrosis (HP:0001395, a Human Phenotype Ontology term): The presence of excessive fibrous connective tissue in the liver. Fibrosis is a reparative or reactive process. Evidence: PCS. Frequency: 2/7. (PMID:19668216)
- Hemifacial spasm (HP:0010828, a Human Phenotype Ontology term): Intermittent clonic or tonic contraction of muscles supplied by facial nerve. Muscles are relaxed in between contractions. Evidence: TAS. (OMIM:213300)
- Abnormality of ocular smooth pursuit (HP:0000617, a Human Phenotype Ontology term): An abnormality of eye movement characterized by impaired smooth-pursuit eye movements. Evidence: IEA. (OMIM:213300)
- Oculomotor apraxia (HP:0000657, a Human Phenotype Ontology term): Ocular motor apraxia is a deficiency in voluntary, horizontal, lateral, fast eye movements (saccades) with retention of slow pursuit movements. The inability to follow objects visually is often compensated by head movements. There may be decreased smooth pursuit, and cancelation of the vestibulo-ocular reflex. Evidence: PCS. Frequency: 7/7. (PMID:19668216)
- Clinodactyly (HP:0030084, a Human Phenotype Ontology term): An angulation of a digit at an interphalangeal joint in the plane of the palm (finger) or sole (toe). Evidence: PCS. Frequency: 1/1. (PMID:29230161)
- Episodic tachypnea (HP:0002876, a Human Phenotype Ontology term): Episodes of very rapid breathing. Evidence: IEA. (OMIM:213300)
- Macrocephaly (HP:0000256, a Human Phenotype Ontology term): Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium. Evidence: IEA. (OMIM:213300)
- Cerebellar vermis hypoplasia (HP:0001320, a Human Phenotype Ontology term): Underdevelopment of the vermis of cerebellum. Evidence: IEA. (OMIM:213300)
- Delayed speech and language development (HP:0000750, a Human Phenotype Ontology term): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: PCS. Frequency: 1/1. (PMID:29230161)
- Nephropathy (HP:0000112, a Human Phenotype Ontology term): A nonspecific term referring to disease or damage of the kidneys. Evidence: PCS. Frequency: 1/1. (PMID:29230161)
- Delayed ability to walk (HP:0031936, a Human Phenotype Ontology term): A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months. Evidence: PCS. Frequency: 1/1. (PMID:29230161)
- Postaxial hand polydactyly (HP:0001162, a Human Phenotype Ontology term): Supernumerary digits located at the ulnar side of the hand (that is, on the side with the fifth finger). Evidence: IEA. (OMIM:213300)
- Enlarged fossa interpeduncularis (HP:0100951, a Human Phenotype Ontology term). Evidence: PCS. (OMIM:213300)
- Ptosis (HP:0000508, a Human Phenotype Ontology term): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: PCS. Frequency: 1/1. (PMID:29230161)
- Impaired smooth pursuit (HP:0007772, a Human Phenotype Ontology term): 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. (OMIM:213300)
- Renal cyst (HP:0000107, a Human Phenotype Ontology term): A fluid filled sac in the kidney. Evidence: PCS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (OMIM:213300)
- Retinal dysplasia (HP:0007973, a Human Phenotype Ontology term): Abnormal growth and differentiation, structure and appearance of the retina present from birth. Evidence: PCS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (OMIM:213300)
- Optic disc pallor (HP:0000543, a Human Phenotype Ontology term): A pale yellow discoloration of the optic disc (the area of the optic nerve head in the retina). The optic disc normally has a pinkish hue with a central yellowish depression. Evidence: PCS. Frequency: 1/7. (PMID:19668216)
- Plagiocephaly (HP:0001357, a Human Phenotype Ontology term): Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape. Evidence: PCS. Frequency: 1/7. (PMID:19668216)
- Postaxial foot polydactyly (HP:0001830, a Human Phenotype Ontology term): Polydactyly of the foot most commonly refers to the presence of six toes on one foot. Postaxial polydactyly affects the lateral ray and the duplication may range from a well-formed articulated digit to a rudimentary digit. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (OMIM:213300)
- Optic disc coloboma (HP:0000588, a Human Phenotype Ontology term): A cleft of the optic nerve that extends inferiorly. Evidence: IEA. (OMIM:213300)
- Self-mutilation (HP:0000742, a Human Phenotype Ontology term): Deliberate harm to one's body resulting in tissue damage, without a conscious intent to die. Evidence: IEA. (OMIM:213300)
- Triangular-shaped open mouth (HP:0200096, a Human Phenotype Ontology term): A facial appearance characterized by a permanently or nearly permanently opened mouth, in which the upper lip is tented in a way that the opened mouth has the appearance of a triangle. Evidence: TAS. (OMIM:213300)
These phenotypes are associated with the disease Joubert syndrome 1 (OMIM:213300, an entry in Online Mendelian Inheritance in Man).