- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:89844)
- 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. Frequency: Very frequent (HP:0040281). (ORPHA:89844)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:89844)
- 4-layered lissencephaly (HP:0006818): A form of lissencephaly in which the cortex is thickened and has four more or less disorganized layers rather than six normal layers resulting from incomplete neuronal migration during brain development. At neuropathological examination, a 4-layered cortex consists of an upper molecular layer, a second thin cellular layer containing pyramidal neurons usually observed in layer V, a third pale poorly cellular layer and a fourth thick deep layer made up of neurons which had failed to migrate. Radiologocally would manifest as agyria or pachygyria with cortical thickness greater than 10 mm. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:89844)
- Primary microcephaly (HP:0011451): Head circumference below 2 standard deviations below the mean for age and gender at birth. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:89844)
- Microlissencephaly (HP:0045028): Severe microcephaly and lissencephaly with granular surfaces with immature cortical plate, reduced in thickness, with focal polymicrogyria and immature small neurons with rare processes, intermingled with a considerable number of glial elements. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:89844)
- Prominent occiput (HP:0000269): Increased convexity of the occiput (posterior part of the skull). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Microretrognathia (HP:0000308): A form of developmental hypoplasia of the mandible in which the mandible is mislocalised posteriorly. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Sloping forehead (HP:0000340): Inclination of the anterior surface of the forehead from the vertical more than two standard deviations above the mean (objective); or apparently excessive posterior sloping of the forehead in a lateral view. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Narrow forehead (HP:0000341): 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Small forehead (HP:0000350): The presence of a forehead that is abnormally small. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Low-set ears (HP:0000369): Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Wide nasal bridge (HP:0000431): Increased breadth of the nasal bridge (and with it, the nasal root). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Wide nose (HP:0000445): Interalar distance more than two standard deviations above the mean for age, i.e., an apparently increased width of the nasal base and alae. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- 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: Frequent (HP:0040282). (ORPHA:89844)
- Intrauterine growth retardation (HP:0001511): An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Abnormal calvaria morphology (HP:0002683): Abnormality of the morphology (structure) of the calvaria (skullcap), that is, of that part of the skull that is made up of the superior portions of the frontal bone, occipital bone, and parietal bones and covers the cranial cavity that contains the brain. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Abnormal muscle tone (HP:0003808). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Severe global developmental delay (HP:0011344): A severe delay in the achievement of motor or mental milestones in the domains of development of a child. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Profound global developmental delay (HP:0012736): A profound delay in the achievement of motor or mental milestones in the domains of development of a child. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:89844)
- Dolichocephaly (HP:0000268): An abnormality of skull shape characterized by a increased anterior-posterior diameter, i.e., an increased antero-posterior dimension of the skull. Cephalic index less than 76%. Alternatively, an apparently increased antero-posterior length of the head compared to width. Often due to premature closure of the sagittal suture. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Abnormal retinal morphology (HP:0000479): A structural abnormality of the retina. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Adducted thumb (HP:0001181): In the resting position, the tip of the thumb is on, or near, the palm, close to the base of the fourth or fifth finger. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Cerebellar atrophy (HP:0001272): Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Agenesis of corpus callosum (HP:0001274): Absence of the corpus callosum as a result of the failure of the corpus callosum to develop, which can be the result of a failure in any one of the multiple steps of callosal development including cellular proliferation and migration, axonal growth or glial patterning at the midline. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Atrial septal defect (HP:0001631): Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Patent foramen ovale (HP:0001655): Failure of the foramen ovale to seal postnatally, leaving a potential conduit between the left and right cardiac atria. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Rocker bottom foot (HP:0001838): The presence of both a prominent heel and a convex contour of the sole. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Respiratory distress (HP:0002098): Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Abnormality of neuronal migration (HP:0002269): An abnormality resulting from an anomaly of neuronal migration, i.e., of the process by which neurons travel from their origin to their final position in the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Cerebral calcification (HP:0002514): The presence of calcium deposition within the cerebrum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
- Hypoplastic spleen (HP:0006270): Underdevelopment of the spleen. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:89844)
These phenotypes are associated with the disease Lissencephaly syndrome, Norman-Roberts type (ORPHA:89844).