- 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: IEA. (OMIM:257300)
- Epicanthus (HP:0000286): A fold of skin starting above the medial aspect of the upper eyelid and arching downward to cover, pass in front of and lateral to the medial canthus. Evidence: IEA. (OMIM:257300)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: PCS. (OMIM:257300)
- 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: 2/10. (PMID:15475955)
- Profound intellectual disability (HP:0002187): Profound intellectual disability (ID) is defined as a type of ID characterized by profoundly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) below 20. Evidence: IEA. (OMIM:257300)
- 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: TAS. (OMIM:257300)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: IEA. (OMIM:257300)
- Cataract (HP:0000518): A cataract is an opacity or clouding that develops in the crystalline lens of the eye or in its capsule. Evidence: IEA. (OMIM:257300)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: IEA. (OMIM:257300)
- 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: IEA. (OMIM:257300)
- Hydrocephalus (HP:0000238): Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation. Evidence: IEA. (OMIM:257300)
- Cerebral hypoplasia (HP:0006872): Underdevelopment of the cerebrum. Evidence: PCS. Frequency: 1/10. (PMID:15475955)
- Postnatal growth retardation (HP:0008897): Slow or limited growth after birth. Evidence: PCS. (OMIM:257300)
- Premature chromatid separation (HP:0200024): The presence of premature sister chromatid segregation. Evidence: TAS. (OMIM:257300)
- Short sternum (HP:0000879): Decreased inferosuperior length of the sternum. Evidence: IEA. (OMIM:257300)
- Pulmonic stenosis (HP:0001642): A narrowing of the right ventricular outflow tract that can occur at the pulmonary valve (valvular stenosis), below the pulmonary valve (infundibular stenosis), or above the pulmonary valve (supravalvar stenosis). Evidence: PCS. Frequency: 1/10. (PMID:15475955)
- 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: IEA. (OMIM:257300)
- 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: IEA. (OMIM:257300)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 9/9. (PMID:15475955)
- Micropenis (HP:0000054): Abnormally small penis. At birth, the normal penis is about 3 cm (stretched length from pubic tubercle to tip of penis) with micropenis less than 2.0-2.5 cm. Evidence: IEA. (OMIM:257300)
- Combined immunodeficiency (HP:0005387): A group of phenotypically heterogeneous genetic disorders characterized by profound deficiencies of T- and B-cell function, which predispose the patients to both infectious and noninfectious complications. Evidence: IEA. (OMIM:257300)
- 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: TAS. (OMIM:257300)
- 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:15475955)
- Triangular mouth (HP:0000207): The presence of a triangular form of the mouth. Evidence: IEA. (OMIM:257300)
- Bifid scrotum (HP:0000048): Midline indentation or cleft of the scrotum. Evidence: IEA. (OMIM:257300)
- Nephroblastoma (HP:0002667): The presence of a nephroblastoma, which is a neoplasm of the kidney that primarily affects children. Evidence: IEA. (OMIM:257300)
- Hypospadias (HP:0000047): Abnormal position of urethral meatus on the ventral penile shaft (underside) characterized by displacement of the urethral meatus from the tip of the glans penis to the ventral surface of the penis, scrotum, or perineum. Evidence: IEA. (OMIM:257300)
- Embryonal rhabdomyosarcoma (HP:0006743). Evidence: PCS. Frequency: 2/10. (PMID:15475955)
- Multicystic kidney dysplasia (HP:0000003): Multicystic dysplasia of the kidney is characterized by multiple cysts of varying size in the kidney and the absence of a normal pelvicaliceal system. The condition is associated with ureteral or ureteropelvic atresia, and the affected kidney is nonfunctional. Evidence: PCS. Frequency: 1/10. (PMID:15475955)
- 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: IEA. (OMIM:257300)
- 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: IEA. (OMIM:257300)
- 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. (OMIM:257300)
- 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: IEA. (OMIM:257300)
- Long philtrum (HP:0000343): 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: IEA. (OMIM:257300)
- 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: IEA. (OMIM:257300)
- 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. (OMIM:257300)
- Ambiguous genitalia (HP:0000062): A genital phenotype that is not clearly assignable to a single gender. Ambiguous genitalia can be evaluated using the Prader scale: Prader 0: Normal female external genitalia. Prader 1: Female external genitalia with clitoromegaly. Prader 2: Clitoromegaly with partial labial fusion forming a funnel-shaped urogenital sinus. Prader 3: Increased phallic enlargement. Complete labioscrotal fusion forming a urogenital sinus with a single opening. Prader 4: Complete scrotal fusion with urogenital opening at the base or on the shaft of the phallus. Prader 5: Normal male external genitalia. The diagnosis of ambiguous genitalia is made for Prader 1-4. Evidence: IEA. (OMIM:257300)
- Hypodysplasia of the corpus callosum (HP:0006849): Developmental defect characterized by a small and malformed corpus callosum. Evidence: IEA. (OMIM:257300)
- Antenatal onset (HP:0030674): Onset prior to birth. Evidence: PCS. Frequency: 9/9. (PMID:15475955)
- 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. (OMIM:257300)
- Leukemia (HP:0001909): A cancer of the blood and bone marrow characterized by an abnormal proliferation of leukocytes. Evidence: IEA. (OMIM:257300)
- Dandy-Walker malformation (HP:0001305): A congenital brain malformation typically characterized by incomplete formation of the cerebellar vermis, dilation of the fourth ventricle, and enlargement of the posterior fossa. In layman's terms, Dandy Walker malformation is a cyst in the cerebellum (typically symmetrical) that is involved with the fourth ventricle. This may interfere with the ability to drain cerebrospinal fluid from the brain, resulting in hydrocephalus. Dandy Walker cysts are formed during early embryonic development, while the brain forms. The cyst in the cerebellum typically has several blood vessels running through it connecting to the brain, thereby prohibiting surgical removal. Evidence: TAS. (OMIM:257300)
- Feeding difficulties in infancy (HP:0008872): Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention. Evidence: IEA. (OMIM:257300)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: PCS. (OMIM:257300)
- Oligohydramnios (HP:0001562): Diminished amniotic fluid volume in pregnancy. Evidence: IEA. (OMIM:257300)
- Cerebellar hypoplasia (HP:0001321): Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time. Evidence: TAS. (OMIM:257300)
- Malar flattening (HP:0000272): Underdevelopment of the malar prominence of the jugal bone (zygomatic bone in mammals), appreciated in profile, frontal view, and/or by palpation. Evidence: IEA. (OMIM:257300)
- Short neck (HP:0000470): Diminished length of the neck. Evidence: IEA. (OMIM:257300)
- 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. (OMIM:257300)
- Depressed nasal bridge (HP:0005280): Posterior positioning of the nasal root in relation to the overall facial profile for age. Evidence: IEA. (OMIM:257300)
- Small for gestational age (HP:0001518): Smaller than normal size according to sex and gestational age related norms, defined as a weight below the 10th percentile for the gestational age. Evidence: PCS. Frequency: 9/9. (PMID:15475955)
- Renal cyst (HP:0000107): A fluid filled sac in the kidney. Evidence: IEA. (OMIM:257300)
- High forehead (HP:0000348): An abnormally increased height of the forehead. Evidence: IEA. (OMIM:257300)
- Intrauterine growth retardation (HP:0001511): An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age. Evidence: PCS. Frequency: 9/9. (PMID:15475955)
- 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: 2/10. (PMID:15475955)
- Cryptorchidism (HP:0000028): Testis in inguinal canal. That is, absence of one or both testes from the scrotum owing to failure of the testis or testes to descend through the inguinal canal to the scrotum. Evidence: IEA. (OMIM:257300)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: PCS. (OMIM:257300)
- Tetraplegia (HP:0002445): Paralysis of all four limbs, and trunk of the body below the level of an associated injury to the spinal cord. The etiology of quadriplegia is similar to that of paraplegia except that the lesion is in the cervical spinal cord rather than in the thoracic or lumbar segments of the spinal cord. Evidence: PCS. Frequency: 2/10. (PMID:15475955)
- Duodenal atresia (HP:0002247): A developmental defect resulting in complete obliteration of the duodenal lumen, that is, an abnormal closure of the duodenum. Evidence: PCS. Frequency: 1/10. (PMID:15475955)
These phenotypes are associated with the disease mosaic variegated aneuploidy syndrome 1 (OMIM:257300).