- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Coarse facial features (HP:0000280): Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Plagiocephaly (HP:0001357): Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Decreased fetal movement (HP:0001558): An abnormal reduction in quantity or strength of fetal movements. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Bradycardia (HP:0001662): A slower than normal heart rate (in adults, slower than 60 beats per minute). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Moderate intellectual disability (HP:0002342): Moderate intellectual disability (ID) is defined as a type of ID characterized by moderately sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 35-49. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Diffuse cerebral atrophy (HP:0002506): Diffuse unlocalised atrophy affecting the cerebrum. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Flat occiput (HP:0005469): Reduced convexity of the occiput (posterior part of skull). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Morning myoclonic jerks (HP:0007000). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Developmental stagnation (HP:0007281): A cessation of the development of a child in the areas of motor skills, speech and language, cognitive skills, and social and/or emotional skills. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Severe intellectual disability (HP:0010864): Severe intellectual disability (ID) is defined as a type of ID characterized by severely sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 20-34. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
- Prominent forehead (HP:0011220): Forward prominence of the entire forehead, due to protrusion of the frontal bone. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2898)
These phenotypes are associated with the disease X-linked intellectual disability-plagiocephaly syndrome (ORPHA:2898).