- 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: 1/1. (PMID:23863341)
- Short foot (HP:0001773): A measured foot length that is more than 2 SD below the mean for a newborn of 27 - 41 weeks gestation, or foot that is less than the 3rd centile for individuals from birth to 16 years of age (objective). Alternatively, a foot that appears disproportionately short (subjective). Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- 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: 10/10. (PMID:28166369)
- Short nose (HP:0003196): Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip. Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- Gastroesophageal reflux (HP:0002020): A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 8/8. (PMID:28166369)
- Infantile spasms (HP:0012469): Infantile spasms represent a subset of "epileptic spasms". Infantile Spasms are epileptic spasms starting in the first year of life (infancy). Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Smooth philtrum (HP:0000319): Flat skin surface, with no ridge formation in the central region of the upper lip between the nasal base and upper vermilion border. Evidence: PCS. Frequency: 4/11. (PMID:23863341;PMID:28166369)
- Broad hallux (HP:0010055): Visible increase in width of the hallux without an increase in the dorso-ventral dimension. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Dental crowding (HP:0000678): Changes in alignment of teeth in the dental arch. Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- Unilateral ptosis (HP:0007687): A unilateral form of ptosis. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Round face (HP:0000311): The facial appearance is more circular than usual as viewed from the front. Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- Retrognathia (HP:0000278): An abnormality in which the mandible is mislocalised posteriorly. Evidence: PCS. Frequency: 2/2. (PMID:26358754;PMID:23863341)
- Posteriorly rotated ears (HP:0000358): A type of abnormal location of the ears in which the position of the ears is characterized by posterior rotation (the superior part of the ears is rotated towards the back of the head, and the inferior part of the ears towards the front). Evidence: PCS. Frequency: 3/10. (PMID:28166369)
- Hirsutism (HP:0001007): Abnormally increased hair growth referring to a male pattern of body hair (androgenic hair). Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Solitary median maxillary central incisor (HP:0006315): A single maxillary central incisor positioned in the midline with morphological symmetry of the crown and bordered by lateral incisors. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Highly arched eyebrow (HP:0002553): Increased height of the central portion of the eyebrow, forming a crescent, semicircular, or inverted U shape. Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 2/2. (PMID:26358754;PMID:23863341)
- Hip dysplasia (HP:0001385): The presence of developmental dysplasia of the hip. Evidence: PCS. Frequency: 2/11. (PMID:23863341;PMID:28166369)
- Downslanted palpebral fissures (HP:0000494): The palpebral fissure inclination is more than two standard deviations below the mean. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Cleft palate (HP:0000175): Cleft palate is a developmental defect of the palate resulting from a failure of fusion of the palatine processes and manifesting as a separation of the roof of the mouth (soft and hard palate). Evidence: PCS. Frequency: 2/10. (PMID:28166369)
- EEG abnormality (HP:0002353): Abnormality observed by electroencephalogram (EEG), which is used to record of the brain's spontaneous electrical activity from multiple electrodes placed on the scalp. Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 11/11. (PMID:26358754;PMID:28166369)
- Choanal atresia (HP:0000453): Absence or abnormal closure of the choana (the posterior nasal aperture). Most embryologists believe that posterior choanal atresia results from a failure of rupture between the 35th and 38th day of fetal life of the partition which separates the bucconasal or buccopharyngeal membranes. The resultant choanal atresia may be unilateral or bilateral, bony or membranous, complete or incomplete. In over 90 per cent of cases the obstruction is bony, while in the remainder it is membranous. The bony type of atresia is commonly located 1-2 mm. anterior to the posterior edge of the hard palate, and the osseous septum varies in thickness from 1 to 10 mm. In the membranous form of choanal atresia the obstruction usually occurs further posteriorly. In approximately one third of cases the atresia is bilateral. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: PCS. Frequency: 2/11. (PMID:26358754;PMID:28166369)
- Deeply set eye (HP:0000490): An eye that is more deeply recessed into the plane of the face than is typical. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- 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: 11/11. (PMID:23863341;PMID:28166369)
- Low anterior hairline (HP:0000294): 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 below the mean. Alternatively, an apparently decreased distance between the hairline and the glabella. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Midface retrusion (HP:0011800): Posterior positions and/or vertical shortening of the infraorbital and perialar regions, or increased concavity of the face and/or reduced nasolabial angle. Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- Tapered finger (HP:0001182): The gradual reduction in girth of the finger from proximal to distal. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- 1-2 toe syndactyly (HP:0010711): Syndactyly with fusion of toes one and two. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Camptodactyly (HP:0012385): The distal interphalangeal joint and/or the proximal interphalangeal joint of the fingers or toes cannot be extended to 180 degrees by either active or passive extension. Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- 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: 2/10. (PMID:28166369)
- Multifocal seizures (HP:0031165): Seizures that start from several different areas of the brain (i.e., with multiple ictal onset locations). Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Semilobar holoprosencephaly (HP:0002507): A type of holoprosencephaly in which the left and right frontal and parietal lobes are fused and the interhemispheric fissure is only present posteriorly. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Hypotelorism (HP:0000601): Interpupillary distance less than 2 SD below the mean (alternatively, the appearance of an decreased interpupillary distance or closely spaced eyes). Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Focal-onset seizure (HP:0007359): A focal-onset seizure is a type of seizure originating within networks limited to one hemisphere. They may be discretely localized or more widely distributed, and may originate in subcortical structures. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Short philtrum (HP:0000322): 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. Frequency: 1/10. (PMID:28166369)
- Triangular face (HP:0000325): Facial contour, as viewed from the front, triangular in shape, with breadth at the temples and tapering to a narrow chin. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Facial asymmetry (HP:0000324): An abnormal difference between the left and right sides of the face. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Widely spaced teeth (HP:0000687): Increased spaces (diastemata) between most of the teeth in the same dental arch. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Hypertonia (HP:0001276): 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: 1/1. (PMID:26358754)
- 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: PCS. Frequency: 2/10. (PMID:28166369)
- Upslanted palpebral fissure (HP:0000582): The palpebral fissure inclination is more than two standard deviations above the mean for age (objective); or, the inclination of the palpebral fissure is greater than typical for age. Evidence: PCS. Frequency: 2/11. (PMID:23863341;PMID:28166369)
- Hypsarrhythmia (HP:0002521): Hypsarrhythmia is abnormal interictal high amplitude waves and a background of irregular spikes. There is continuous (during wakefulness), high-amplitude (>200 Hz), generalized polymorphic slowing with no organized background and multifocal spikes demonstrated by electroencephalography (EEG). Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- 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: 1/10. (PMID:28166369)
- Narrow nose (HP:0000460): Interalar distance more than 2 SD below the mean for age, or alternatively, an apparently decreased width of the nasal base and alae. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Seizure cluster (HP:0033349): A fourfold or greater increase of usual seizure frequency within a 3-day period, where the patient demonstrates full recovery between seizure events within the cluster. The seizure cluster should be recognizable by the primary clinician, carer or patient. Evidence: PCS. Frequency: 7/10. (PMID:28166369)
- Ventricular septal defect (HP:0001629): A hole between the two bottom chambers (ventricles) of the heart. The defect is centered around the most superior aspect of the ventricular septum. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Reduced eye contact (HP:0000817): A reduced frequency or duration of eye contact. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Motor stereotypy (HP:0000733): Use of the same abnormal action in response to certain triggers or at random. They may be used as a way to regulate one's internal state but must otherwise have no apparent functional purpose. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Thin upper lip vermilion (HP:0000219): Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective). Evidence: PCS. Frequency: 2/10. (PMID:28166369)
- Clinodactyly (HP:0030084): An angulation of a digit at an interphalangeal joint in the plane of the palm (finger) or sole (toe). Evidence: PCS. Frequency: 1/1. (PMID:23863341)
- 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: PCS. Frequency: 1/10. (PMID:28166369)
- X-linked dominant inheritance (HP:0001423): A mode of inheritance that is observed for dominant traits related to a gene encoded on the X chromosome. In the context of medical genetics, X-linked dominant disorders tend to manifest very severely in affected males. The severity of manifestation in females may depend on the degree of skewed X inactivation. Evidence: PCS. (PMID:23863341)
- Congenital diaphragmatic hernia (HP:0000776): The presence of a hernia of the diaphragm present at birth. Evidence: PCS. Frequency: 1/1. Onset: Congenital onset (HP:0003577). (PMID:23863341)
- Axial hypotonia (HP:0008936): Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Overfolded helix (HP:0000396): A condition in which the helix is folded over to a greater degree than normal. That is, excessive curling of the helix edge, whereby the free edge is parallel to the plane of the ear. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- 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: 1/1. (PMID:23863341)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Talipes (HP:0001883): A deformity of foot and ankle that has different subtypes that are talipes equinovarus, talipes equinovalgus, talipes calcaneovarus and talipes calcaneovalgus. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- 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: 1/1. Onset: Infantile onset (HP:0003593). (PMID:23863341)
- Spastic tetraparesis (HP:0001285): Spastic weakness affecting all four limbs. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Partial anomalous pulmonary venous return (HP:0010773): A form of anomalous pulmonary venous return in which not all pulmonary veins drain abnormally. Partial anomalous pulmonary venous return frequently involves one or both of the veins from one lung. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- 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: PCS. Frequency: 1/1. (PMID:26358754)
- Contracture of the proximal interphalangeal joint of the 3rd finger (HP:0009471): Chronic loss of joint motion of the proximal interphalangeal joint of the 3rd finger due to structural changes in non-bony tissue. Evidence: PCS. Frequency: 1/10. (PMID:28166369)
- Intrauterine growth retardation (HP:0001511): An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Synophrys (HP:0000664): Meeting of the medial eyebrows in the midline. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Small hand (HP:0200055): Disproportionately small hand. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: PCS. Frequency: 1/1. (PMID:26358754)
- 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: PCS. Frequency: 3/10. (PMID:28166369)
These phenotypes are associated with the disease developmental and epileptic encephalopathy, 85, with or without midline brain defects (OMIM:301044).