- Sloping forehead (HP:0000340): Inclination of the anterior surface of the forehead from the vertical more than two standard deviations above the mean (objective); or apparently excessive posterior sloping of the forehead in a lateral view. Evidence: PCS. Frequency: 1/1. (PMID:27737959)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 1/1. (PMID:27737959)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 1/1. (PMID:27737959)
- 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: PCS. Frequency: 1/1. (PMID:27737959)
- 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. Frequency: 1/1. (PMID:27737959)
- 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: 1/1. (PMID:27737959)
- Autistic behavior (HP:0000729): Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior. Evidence: PCS. Frequency: 1/1. (PMID:27737959)
- Primary microcephaly (HP:0011451): Head circumference below 2 standard deviations below the mean for age and gender at birth. Evidence: PCS. Frequency: 1/1. (PMID:27737959)
- 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:27737959)
These phenotypes are associated with the disease microcephaly 21, primary, autosomal recessive (OMIM:617983).