- Downslanted palpebral fissures (HP:0000494): The palpebral fissure inclination is more than two standard deviations below the mean. Evidence: PCS. Frequency: 1/6. (PMID:32197073)
- 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: 6/6. (PMID:32197073)
- Anteverted nares (HP:0000463): 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: PCS. Frequency: 1/6. (PMID:32197073)
- Deep philtrum (HP:0002002): Accentuated, prominent philtral ridges giving rise to an exaggerated groove in the midline between the nasal base and upper vermillion border. Evidence: PCS. Frequency: 1/6. (PMID:32197073)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: PCS. Frequency: 2/6. (PMID:32197073)
- 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: 2/6. (PMID:32197073)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. Frequency: 5/6. (PMID:32197073)
- Cerebral cortical atrophy (HP:0002120): Atrophy of the cortex of the cerebrum. Evidence: PCS. Frequency: 1/6. (PMID:32197073)
- Deeply set eye (HP:0000490): An eye that is more deeply recessed into the plane of the face than is typical. Evidence: PCS. Frequency: 1/6. (PMID:32197073)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 3/4. (PMID:32197073)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 6/6. (PMID:32197073)
- 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:32197073)
- High anterior hairline (HP:0009890): Distance between the hairline (trichion) and the glabella (the most prominent point on the frontal bone above the root of the nose), in the midline, more than two SD above the mean. Alternatively, an apparently increased distance between the hairline and the glabella. Evidence: IEA. Frequency: 1/6. (PMID:32197073)
- Inappropriate laughter (HP:0000748): Laughing that may be excessive and/or inappropriate in context (e.g., laughing at a funeral while others are crying). Evidence: PCS. Frequency: 2/6. (PMID:32197073)
- 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: 3/6. (PMID:32197073)
- Chiari type I malformation (HP:0007099): Arnold-Chiari type I malformation refers to a relatively mild degree of herniation of the posteroinferior region of the cerebellum (the cerebellar tonsils) into the cervical canal with little or no displacement of the fourth ventricle. It is characterized by one or both pointed (not rounded) cerebellar tonsils that project 5 mm below the foramen magnum, measured by a line drawn from the basion to the opisthion (McRae Line). Evidence: PCS. Frequency: 1/6. (PMID:32197073)
- Downturned corners of mouth (HP:0002714): A morphological abnormality of the mouth in which the angle of the mouth is downturned. The oral commissures are positioned inferior to the midline labial fissure. Evidence: TAS. Frequency: 1/6. (OMIM:618859)
- Bilateral ptosis (HP:0001488). Evidence: PCS. Frequency: 1/6. (PMID:32197073)
- 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: PCS. Frequency: 4/6. (PMID:32197073)
- Autosomal dominant inheritance (HP:0000006): 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 heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:32197073)
- Brachycephaly (HP:0000248): An abnormality of skull shape characterized by a decreased anterior-posterior diameter. That is, a cephalic index greater than 81%. Alternatively, an apparently shortened anteroposterior dimension (length) of the head compared to width. Evidence: PCS. Frequency: 1/6. (PMID:32197073)
- 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: 6/6. (PMID:32197073)
These phenotypes are associated with the disease neurodevelopmental disorder with or without autistic features and/or structural brain abnormalities (OMIM:618859).