- Bilateral tonic-clonic seizure (HP:0002069): A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- Poor speech (HP:0002465). Evidence: TAS. (PMID:29603516)
- Abnormal ear morphology (HP:0031703): Any structural anomaly of the ear. Evidence: TAS. (OMIM:618010)
- Dysplastic corpus callosum (HP:0006989): Dysplasia and dysgenesis of the corpus callosum are nonspecific descriptions that imply defective development of the corpus callosum. The term dysplasia is applied when the morphology of the corpus callosum is altered as a congenital trait. For instance, the corpus callosum may be hump-shaped, kinked, or a striped corpus callosum that lacks an anatomically distinct genu and splenium. Evidence: PCS. Frequency: 2/2. (PMID:29573052)
- Generalized myoclonic seizure (HP:0002123): A generalized myoclonic seizure is a type of generalized motor seizure characterized by bilateral, sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- 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: 2/2. (PMID:29573052)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (PMID:29603516)
- Dry skin (HP:0000958): Skin characterized by the lack of natural or normal moisture. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 2/2. (PMID:29573052)
- 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. Frequency: 2/2. (PMID:29573052)
- Specific learning disability (HP:0001328): Impairment of certain skills such as reading or writing, coordination, self-control, or attention that interfere with the ability to learn. The impairment is not related to a global deficiency of intelligence. Evidence: TAS. (PMID:29603516)
- High palate (HP:0000218): Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective). Evidence: TAS. (PMID:29603516)
- Clinodactyly of the 5th toe (HP:0001864): Bending or curvature of a fifth toe in the tibial direction (i.e., towards the big toe). Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- Osteomyelitis (HP:0002754): Osteomyelitis is an inflammatory process accompanied by bone destruction and caused by an infecting microorganism. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- Abnormality of alkaline phosphatase level (HP:0004379): An abnormality of alkaline phosphatase level. Evidence: PCS. Frequency: 0/2. (PMID:29573052)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- Hypertriglyceridemia (HP:0002155): An abnormal increase in the level of triglycerides in the blood. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- 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: 1/2. (PMID:29573052)
- Nevus spilus (HP:0025510): A tan, regularly bordered patch with darker macules within the lesion. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- 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: IEA. Frequency: Very rare (HP:0040284). (OMIM:618010)
- Overfriendliness (HP:0100025): A form of hypersociability that presents as mostly inappropriate friendliness towards others. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- 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:29573052)
- Clinodactyly of the 5th finger (HP:0004209): Clinodactyly refers to a bending or curvature of the fifth finger in the radial direction (i.e., towards the 4th finger). Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- Chronic otitis media (HP:0000389): Chronic otitis media refers to fluid, swelling, or infection of the middle ear that does not heal and may cause permanent damage to the ear. Evidence: PCS. Frequency: 1/2. (PMID:29573052)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: TAS. (PMID:29573052)
These phenotypes are associated with the disease glycosylphosphatidylinositol biosynthesis defect 17 (OMIM:618010).