Phenotypes associated with the disease Joubert syndrome 21 (OMIM:615636):
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: TAS. (OMIM:615636)
- Pulmonary hypoplasia (HP:0002089). Evidence: PCS. Frequency: 4/19. (PMID:24360808)
- Strabismus (HP:0000486): 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: TAS. (OMIM:615636)
- Hypoplasia of the brainstem (HP:0002365): Underdevelopment of the brainstem. Evidence: TAS. (OMIM:615636)
- Bell-shaped thorax (HP:0001591): The rib cage has the shape of a wide mouthed bell. That is, the superior portion of the rib cage is constricted, followed by a convex region, and the inferior portion of the rib cage expands again to have a large diameter. Evidence: PCS. Frequency: 4/19. (PMID:24360808)
- 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: 1/18. (PMID:24360808)
- 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: TAS. (OMIM:615636)
- Occipital encephalocele (HP:0002085): A type of encephalocele (that is, a a protrusion of part of the cranial contents including brain tissue through a congenital opening in the cranium, typically covered with skin or mucous membrane) in the occipital region of the skull. Occipital encephalocele presents as a midline swelling over the occipital bone. It is usually covered with normal full-thickness scalp. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:615636)
- 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. (OMIM:615636)
- Encephalocele (HP:0002084): A neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull. Evidence: PCS. Frequency: 1/18. (PMID:24360808)
- Elongated superior cerebellar peduncle (HP:0011933): Increased length of the superior cerebellar peduncle. Evidence: PCS. Frequency: 0/10. (PMID:24360808)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. Frequency: 6/18. (PMID:24360808)
- Hyperechogenic kidneys (HP:0004719): An increase in amplitude of waves returned in ultrasonography of the kidney, which is generally displayed as increased brightness of the signal. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:615636)
- Oculomotor apraxia (HP:0000657): 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: 4/18. (PMID:24360808)
- 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: PCS. Frequency: 4/19. (PMID:24360808)
- 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: 2/19. (PMID:24360808)
- Short ribs (HP:0000773): Reduced rib length. Evidence: PCS. Frequency: 4/19. (PMID:24360808)
- 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. (OMIM:615636)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: PCS. Frequency: 1/19. (PMID:24360808)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 1/19. (PMID:24360808)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: TAS. (OMIM:615636)
- 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: 19/19. (PMID:24360808)
- Dyspnea (HP:0002094): Difficult or labored breathing. Dyspnea is a subjective feeling only the patient can rate, e.g., on a Borg scale. Evidence: TAS. (OMIM:615636)
- Megalopapilla (HP:0034302): A congenitally anomalous enlarged optic disc (surface area greater than 2.50 square millimeters). It is considered to be a normal variant without physiological defects. Evidence: PCS. Frequency: 1/19. (PMID:24360808)
- Chronic sinusitis (HP:0011109): A chronic form of sinusitis. Evidence: PCS. Frequency: 2/19. (PMID:24360808)
- Posterior fossa cyst (HP:0007291): A discrete posterior fossa cerebrospinal fluid (CSF) collection that does not communicate directly with the fourth ventricle. Evidence: TAS. (OMIM:615636)
- Anophthalmia (HP:0000528): Absence of the globe or eyeball. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:615636)
- Sensorineural hearing impairment (HP:0000407): A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve. Evidence: PCS. Frequency: 2/19. (PMID:24360808)
- Ptosis (HP:0000508): 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: 15/18. (PMID:24360808)
- Renal cyst (HP:0000107): A fluid filled sac in the kidney. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:615636)
- 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:24360808)
- 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: PCS. Frequency: 1/19. (PMID:24360808)
- Retinopathy (HP:0000488): Any noninflammatory disease of the retina. This nonspecific term is retained here because of its wide use in the literature, but if possible new annotations should indicate the precise type of retinal abnormality. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:615636)
- Single naris (HP:0009932): The presence of only a single nostril. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:615636)
- Apnea (HP:0002104): Lack of breathing with no movement of the respiratory muscles and no exchange of air in the lungs. This term refers to a disposition to have recurrent episodes of apnea rather than to a single event. Evidence: TAS. (OMIM:615636)