- Echolalia (HP:0010529): Echolalia is the automatic imitative repetition of sounds, words, or phrases in the absence of explicit awareness. The repeated words or phrases are typically odd or used in a non-social manner. These can be words or phrases that the affected individual has heard or invented. Evidence: PCS. (PMID:23065719)
- 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:615516)
- Narrow palate (HP:0000189): Width of the palate more than 2 SD below the mean (objective) or apparently decreased palatal width (subjective). Evidence: TAS. (OMIM:615516)
- Delayed speech and language development (HP:0000750): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: PCS. Frequency: 7/7. (PMID:23065719)
- Delayed ability to walk (HP:0031936): 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: 7/7. (PMID:23065719)
- 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: Occasional (HP:0040283). (OMIM:615516)
- Febrile seizure (within the age range of 3 months to 6 years) (HP:0002373): A febrile seizure is any type of seizure (most often a generalized tonic-clonic seizure) occurring with fever (at least 38 degrees Celsius) but in the absence of central nervous system infection, severe metabolic disturbance or other alternative precipitant in children between the ages of 3 months and 6 years. Evidence: PCS. Frequency: 2/7. (PMID:23065719)
- 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: 7/7. (PMID:23065719)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: TAS. (OMIM:615516)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (OMIM:615516)
- Diminished ability to concentrate (HP:0031987): The inability to focus or concentrate on a specific task, activity, or object. The subject may find themselves unable to grasp or understand written text and re-reads frequently without understanding. Familiar tasks or activities are severely compromised due to the lack of ability to concentrate. Thinking through multi-step problems is typically very difficult or impossible, leading to avoidance of such activities. Evidence: IEA. (OMIM:615516)
- Recurrent hand flapping (HP:0100023): A type of repetitive behavior in which the affected individual repeatedly waves the hands and/or arms rhythmically. Evidence: PCS. (PMID:23065719)
- 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: PCS. (PMID:23065719)
- Autistic behavior (HP:0000729): Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior. Evidence: PCS. Frequency: 6/7. (PMID:23065719)
- Blue irides (HP:0000635): A markedly blue coloration of the iris. Evidence: TAS. (OMIM:615516)
- 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:23065719)
- Unsteady gait (HP:0002317). Evidence: PCS. Frequency: 6/7. (PMID:23065719)
- Neonatal hypotonia (HP:0001319): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period. Evidence: PCS. Frequency: 4/7. Onset: Neonatal onset (HP:0003623). (PMID:23065719)
- Sandal gap (HP:0001852): A widely spaced gap between the first toe (the great toe) and the second toe. Evidence: TAS. (OMIM:615516)
- Plagiocephaly (HP:0001357): Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape. Evidence: TAS. (OMIM:615516)
- Hyperactivity (HP:0000752): Hyperactivity is a condition characterized by constant and unusually high levels of activity, even in situations where it is deemed inappropriate. Evidence: TAS. (OMIM:615516)
- Mandibular prognathia (HP:0000303): Abnormal prominence of the chin related to increased length of the mandible. Evidence: TAS. (OMIM:615516)
- 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: PCS. Frequency: 7/7. (PMID:23065719)
- Self-mutilation (HP:0000742): Deliberate harm to one's body resulting in tissue damage, without a conscious intent to die. Evidence: PCS. Frequency: 4/7. (PMID:23065719)
These phenotypes are associated with the disease developmental delay with autism spectrum disorder and gait instability (OMIM:615516).