- Wide mouth (HP:0000154): Distance between the oral commissures more than 2 SD above the mean. Alternatively, an apparently increased width of the oral aperture (subjective). Evidence: PCS. (OMIM:309545)
- Square face (HP:0000321): Facial contours, as viewed from the front, show a broad upper face/cranium and lower face/mandible, creating a square appearance. Evidence: IEA. (OMIM:309545)
- 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: PCS. (OMIM:309545)
- 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:309545)
- Aphasia (HP:0002381): An acquired language impairment of some or all of the abilities to produce or comprehend speech and to read or write. Evidence: IEA. (OMIM:309545)
- Recurrent infections (HP:0002719): Increased susceptibility to infections as manifested by repeated bouts of infection. Evidence: IEA. (OMIM:309545)
- Postnatal growth retardation (HP:0008897): Slow or limited growth after birth. Evidence: PCS. (OMIM:309545)
- X-linked inheritance (HP:0001417): A mode of inheritance that is observed for traits related to a gene encoded on the X chromosome. Evidence: IEA. (OMIM:309545)
- Thick lower lip vermilion (HP:0000179): Increased thickness of the lower lip, leading to a prominent appearance of the lower lip. The height of the vermilion of the lower lip in the midline is more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the lower lip in the frontal view (subjective). Evidence: PCS. (OMIM:309545)
- 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: IEA. (OMIM:309545)
- Mandibular prognathia (HP:0000303): Abnormal prominence of the chin related to increased length of the mandible. Evidence: IEA. (OMIM:309545)
- Thick upper lip vermilion (HP:0000215): Height of the vermilion of the upper lip in the midline more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the upper lip in the frontal view (subjective). Evidence: PCS. (OMIM:309545)
- 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: TAS. (OMIM:309545)
These phenotypes are associated with the disease syndromic X-linked intellectual disability 12 (OMIM:309545).