- Narrow mouth (HP:0000160): Distance between the commissures of the mouth more than 2 SD below the mean. Alternatively, an apparently decreased width of the oral aperture (subjective). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:83473)
- Macrocephaly (HP:0000256): Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:83473)
- 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: Frequent (HP:0040282). (ORPHA:83473)
- High forehead (HP:0000348): An abnormally increased height of the forehead. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- Telecanthus (HP:0000506): Distance between the inner canthi more than two standard deviations above the mean (objective); or, apparently increased distance between the inner canthi. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- Postaxial hand polydactyly (HP:0001162): Supernumerary digits located at the ulnar side of the hand (that is, on the side with the fifth finger). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:83473)
- 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:83473)
- Megalencephaly (HP:0001355): Diffuse enlargement of the entire cerebral hemispheres leading to macrocephaly (with or without overlying cortical dysplasia). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:83473)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- Mitral regurgitation (HP:0001653): An abnormality of the mitral valve characterized by insufficiency or incompetence of the mitral valve resulting in retrograde leaking of blood through the mitral valve upon ventricular contraction. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- Abnormal cardiac septum morphology (HP:0001671): An anomaly of the intra-atrial or intraventricular septum. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- Polymicrogyria (HP:0002126): Polymicrogyria is a congenital malformation of the cerebral cortex characterized by abnormal cortical layering (lamination) and an excessive number of small gyri (folds). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:83473)
- Abnormal nasal morphology (HP:0005105). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- Depressed nasal bridge (HP:0005280): Posterior positioning of the nasal root in relation to the overall facial profile for age. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
- Abnormal localization of kidney (HP:0100542): An abnormal site of the kidney. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:83473)
These phenotypes are associated with the disease Megalencephaly-polymicrogyria-postaxial polydactyly-hydrocephalus syndrome (ORPHA:83473).