- Alobar holoprosencephaly (HP:0006988): A type of holoprosencephaly characterized by the presence of a single ventricle and no separation of the cerebral hemisphere. The single midline ventricle is often greatly enlarged. Evidence: PCS. Frequency: 2/4. (PMID:10369266)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 4/4. (PMID:10369266)
- Cyclopia (HP:0009914): Cyclopia is a congenital abnormality in which there is only one eye. That eye is centrally placed in the area normally occupied by the root of the nose. Evidence: IEA. (OMIM:157170)
- Anterior pituitary agenesis (HP:0010626): Absence of the anterior pituitary gland resulting from a developmental defect. Evidence: TAS. (OMIM:157170)
- Single ventricle (HP:0001750): The presence of only one working lower chamber in the heart, usually with a virtual absence of the ventricular septum and usually present in conjunction with double inlet left or right ventricle. Evidence: IEA. (OMIM:157170)
- 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: IEA. (OMIM:157170)
- Median cleft upper lip (HP:0000161): A type of cleft lip presenting as a midline (median) gap in the upper lip. Evidence: TAS. (OMIM:157170)
- 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: IEA. (OMIM:157170)
- Hypotonia (HP:0001252): 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: IEA. (OMIM:157170)
- Proboscis (HP:0012806): A fleshy, tube-like structure usually located in the midline of the face or just to one side of the midline. Evidence: IEA. (OMIM:157170)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: TAS. (OMIM:157170)
- Absent nasal septal cartilage (HP:0005273): Lack of the cartilage of the nasal septum. Evidence: IEA. (OMIM:157170)
- Aplasia of the nasal bone (HP:0010941): Absence of the nasal bone. Evidence: PCS. Frequency: 1/4. (PMID:10369266)
- Typified by incomplete penetrance (HP:0003829): Description of conditions in which not all individuals with a given genotype exhibit the disease. Penetrance is the proportion that develop disease given a lifespan of 80 years. Evidence: IEA. (OMIM:157170)
- Iris coloboma (HP:0000612): A coloboma of the iris. Evidence: PCS. Frequency: 1/4. (PMID:10369266)
- Adrenal hypoplasia (HP:0000835): Developmental hypoplasia of the adrenal glands. Evidence: IEA. (OMIM:157170)
- Diabetes insipidus (HP:0000873): A state of excessive water intake and hypotonic (dilute) polyuria. Diabetes insipidus may be due to failure of vasopressin (AVP) release (central or neurogenic diabetes insipidus) or to a failure of the kidney to respond to AVP (nephrogenic diabetes insipidus). Evidence: IEA. (OMIM:157170)
- Sporadic (HP:0003745): Cases of the disease in question occur without a previous family history, i.e., as isolated cases without being transmitted from a parent and without other siblings being affected. Evidence: IEA. (OMIM:157170)
- Constipation (HP:0002019): Infrequent or difficult evacuation of feces. Evidence: IEA. (OMIM:157170)
- 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: IEA. (OMIM:157170)
- 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: 2/4. (PMID:10369266)
- Submucous cleft hard palate (HP:0000176): Hard-palate submucous clefts are characterized by bony defects in the midline of the bony palate that are covered by the mucous membrane of the roof of the mouth. It may be possible to detect a submucous cleft hard palate upon palpation as a notch in the bony palate. Evidence: IEA. (OMIM:157170)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 2/4. (PMID:10369266)
- Remnants of the hyaloid vascular system (HP:0007968): Persistence of the hyaloid artery, which is the embryonic artery that runs from the optic disc to the posterior lens capsule may persist; the site of attachment may form an opacity. The hyaloid artery is a branch of the ophthalmic artery, and usually regresses completely before birth. This features results from a failure of regression of the hyaloid vessel, which supplies the primary vitreous during embryogenesis and normally regresses in the third trimester of pregnancy, leading to a particular form of posterior cataract. Evidence: PCS. Frequency: 1/4. (PMID:10369266)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: IEA. (OMIM:157170)
- 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: IEA. (OMIM:157170)
- Holoprosencephaly (HP:0001360): Holoprosencephaly is a structural anomaly of the brain in which the developing forebrain fails to divide into two separate hemispheres and ventricles. Evidence: PCS. (PMID:10369266)
- Bifid uvula (HP:0000193): Uvula separated into two parts most easily seen at the tip. Evidence: IEA. (OMIM:157170)
- 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: 1/1. (PMID:10369266)
- 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:157170)
- 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: 1/4. (PMID:10369266)
- Aplasia of the premaxilla (HP:0010757): Absence of the premaxilla, which is the embryonic structure that forms the anterior part of the maxilla. Evidence: PCS. Frequency: 1/4. (PMID:10369266)
- Bilateral cleft lip (HP:0100336): A non-midline cleft of the upper lip on the left and right sides. Evidence: PCS. Frequency: 3/4. (PMID:10369266)
- Bilateral cleft palate (HP:0100337): Nonmidline cleft palate on the left and right sides. Evidence: PCS. Frequency: 3/4. (PMID:10369266)
- Median cleft palate (HP:0009099): Cleft palate of the midline of the palate. Evidence: TAS. (OMIM:157170)
- 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: 4/4. (PMID:10369266)
- Microphthalmia (HP:0000568): A developmental anomaly characterized by abnormal smallness of one or both eyes. Evidence: PCS. Frequency: 1/4. (PMID:10369266)
- 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: 1/4. (PMID:10369266)
- Proptosis (HP:0000520): An eye that is protruding anterior to the plane of the face to a greater extent than is typical. Evidence: PCS. Frequency: 2/4. (PMID:10369266)
- Autosomal dominant inheritance (HP:0000006): 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:10369266)
- Chorioretinal coloboma (HP:0000567): Absence of a region of the retina, retinal pigment epithelium, and choroid. Evidence: PCS. Frequency: 1/4. (PMID:10369266)
These phenotypes are associated with the disease holoprosencephaly 2 (OMIM:157170).