- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1723)
- 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:1723)
- 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:1723)
- Oligohydramnios (HP:0001562): Diminished amniotic fluid volume in pregnancy. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1723)
- Delayed gross motor development (HP:0002194): A type of motor delay characterized by a delay in acquiring the ability to control the large muscles of the body for walking, running, sitting, and crawling. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1723)
- Postnatal growth retardation (HP:0008897): Slow or limited growth after birth. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1723)
- 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. Frequency: Frequent (HP:0040282). (ORPHA:1723)
- Hernia (HP:0100790). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1723)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- 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:1723)
- Microphthalmia (HP:0000568): A developmental anomaly characterized by abnormal smallness of one or both eyes. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Preaxial hand polydactyly (HP:0001177): Supernumerary digits located at the radial side of the hand. Polydactyly (supernumerary digits) involving the thumb occurs in many distinct forms of high variability and severity. Ranging from fleshy nubbins over varying degrees of partial duplication/splitting to completely duplicated or even triplicated thumbs or preaxial (on the radial side of the hand) supernumerary digits. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Abnormal heart morphology (HP:0001627): Any structural anomaly of the heart. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Aganglionic megacolon (HP:0002251): An abnormality resulting from a lack of intestinal ganglion cells (i.e., an aganglionic section of bowel) that results in bowel obstruction with enlargement of the colon. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Spina bifida (HP:0002414): Incomplete closure of the embryonic neural tube, whereby some vertebral arches remain unfused and open. The mildest form is spina bifida occulta, followed by meningocele and meningomyelocele. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Intestinal malrotation (HP:0002566): An abnormality of the intestinal rotation and fixation that normally occurs during the development of the gut. This can lead to volvulus, or twisting of the intestine that causes obstruction and necrosis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Hypoplasia of the radius (HP:0002984): Underdevelopment of the radius. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Hypoplasia of the ulna (HP:0003022): Underdevelopment of the ulna. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Neurodevelopmental delay (HP:0012758): Neurodevelopmental delay (NDD) refers to delays in the maturation of the brain and central nervous system; infants and young children with NDD may experience delays in the development of one or more skills including gross motor abilities, fine-motor coordination, language abilities and ability to solve increasingly complex problems. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Thin corpus callosum (HP:0033725): An abnormally thin corpus callous, due to atrophy, hypoplasia or agenesis. This term is intended to be used in situations where it is not known if thinning of the corpus callosum (for instance, as visualized by magnetic resonance tomography) is due to abnormal development (e.g. a leukodystrophy) or atrophy following normal development (e.g. neurodegeneration). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Neural tube defect (HP:0045005): A neural tube defect arises when the neural tube, the embryonic precursor of the brain and spinal cord, fails to close during neurulation. The cranial region (anencephaly) or the low spine (open spina bifida; myelomeningocele) are most commonly affected although, in the severe NTD craniorachischisis, almost the entire neural tube remains open, from midbrain to low spine. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
- Cleft lip (HP:0410030): A gap in the lip or lips. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1723)
These phenotypes are associated with the disease Mosaic trisomy 2 syndrome (ORPHA:1723).