- Narrow forehead (HP:0000341, a Human Phenotype Ontology term): Width of the forehead or distance between the frontotemporales is more than two standard deviations below the mean (objective); or apparently narrow intertemporal region (subjective). Evidence: PCS. (PMID:34314705)
- Hypertonia (HP:0001276, a Human Phenotype Ontology term): A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move. Evidence: PCS. Frequency: 2/15. (PMID:34314705)
- Astigmatism (HP:0000483, a Human Phenotype Ontology term): A type of refraction error associated with abnormal curvatures on the anterior and/or posterior surface of the cornea. Evidence: PCS. Frequency: 4/15. (PMID:34314705)
- Long philtrum (HP:0000343, a Human Phenotype Ontology term): Distance between nasal base and midline upper lip vermilion border more than 2 SD above the mean. Alternatively, an apparently increased distance between nasal base and midline upper lip vermilion border. Evidence: PCS. (PMID:34314705)
- Large fleshy ears (HP:0002265, a Human Phenotype Ontology term). Evidence: PCS. (PMID:34314705)
- 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: 7/15. (PMID:34314705)
- Inability to walk (HP:0002540, a Human Phenotype Ontology term): Incapability to ambulate. Evidence: PCS. Frequency: 3/15. (PMID:34314705)
- Delayed CNS myelination (HP:0002188, a Human Phenotype Ontology term): Delayed myelination in the central nervous system. Evidence: PCS. (PMID:34314705)
- Hypermetropia (HP:0000540, a Human Phenotype Ontology term): An abnormality of refraction characterized by the ability to see objects in the distance clearly, while objects nearby appear blurry. Evidence: PCS. Frequency: 4/15. (PMID:34314705)
- Seizure (HP:0001250, a Human Phenotype Ontology term): 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: 6/15. (PMID:34314705)
- 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: PCS. Frequency: 11/15. (PMID:34314705)
- Infantile onset (HP:0003593, a Human Phenotype Ontology term): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. (PMID:34314705)
- 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. (PMID:34314705)
- Coarse facial features (HP:0000280, a Human Phenotype Ontology term): Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues. Evidence: PCS. (PMID:34314705)
- Failure to thrive (HP:0001508, a Human Phenotype Ontology term): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. (PMID:34314705)
- Ventriculomegaly (HP:0002119, a Human Phenotype Ontology term): An increase in size of the ventricular system of the brain. Evidence: PCS. (PMID:34314705)
- Retrognathia (HP:0000278, a Human Phenotype Ontology term): An abnormality in which the mandible is mislocalised posteriorly. Evidence: PCS. (PMID:34314705)
- 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: 9/9. (PMID:34314705)
- Myopathic facies (HP:0002058, a Human Phenotype Ontology term): A facial appearance characteristic of myopathic conditions. The face appears expressionless with sunken cheeks, bilateral ptosis, and inability to elevate the corners of the mouth, due to muscle weakness. Evidence: PCS. (PMID:34314705)
- Microcephaly (HP:0000252, a Human Phenotype Ontology term): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 5/15. (PMID:34314705)
- 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: 15/15. (PMID:34314705)
- Wide nasal bridge (HP:0000431, a Human Phenotype Ontology term): Increased breadth of the nasal bridge (and with it, the nasal root). Evidence: PCS. (PMID:34314705)
- Absent speech (HP:0001344, a Human Phenotype Ontology term): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 4/15. (PMID:34314705)
- Everted lower lip vermilion (HP:0000232, a Human Phenotype Ontology term): An abnormal configuration of the lower lip such that it is turned outward i.e., everted, with the Inner aspect of the lower lip vermilion (normally opposing the teeth) being visible in a frontal view. Evidence: PCS. (PMID:34314705)
- Cerebellar hypoplasia (HP:0001321, a Human Phenotype Ontology term): Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time. Evidence: PCS. Frequency: 3/13. (PMID:34314705)
- Feeding difficulties (HP:0011968, a Human Phenotype Ontology term): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. (PMID:34314705)
- 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: 15/15. (PMID:34314705)
- Autistic behavior (HP:0000729, a Human Phenotype Ontology term): 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. (PMID:34314705)
- Prominent nasal bridge (HP:0000426, a Human Phenotype Ontology term): Anterior positioning of the nasal root in comparison to the usual positioning for age. Evidence: PCS. (PMID:34314705)
- Short philtrum (HP:0000322, a Human Phenotype Ontology term): Distance between nasal base and midline upper lip vermilion border more than 2 SD below the mean. Alternatively, an apparently decreased distance between nasal base and midline upper lip vermilion border. Evidence: PCS. (PMID:34314705)
- Attention deficit hyperactivity disorder (HP:0007018, a Human Phenotype Ontology term): Attention deficit hyperactivity disorder (ADHD) manifests at age 2-3 years or by first grade at the latest. The main symptoms are distractibility, impulsivity, hyperactivity, and often trouble organizing tasks and projects, difficulty going to sleep, and social problems from being aggressive, loud, or impatient. Evidence: PCS. (PMID:34314705)
- Autosomal dominant inheritance (HP:0000006, 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 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:34314705)
- Myopia (HP:0000545, a Human Phenotype Ontology term): An abnormality of refraction characterized by the ability to see objects nearby clearly, while objects in the distance appear blurry. Evidence: PCS. Frequency: 4/15. (PMID:34314705)
- Tremor (HP:0001337, a Human Phenotype Ontology term): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: PCS. (PMID:34314705)
These phenotypes are associated with the disease intellectual developmental disorder with hypotonia, impaired speech, and dysmorphic facies (OMIM:619556, an entry in Online Mendelian Inheritance in Man).