- Poor speech (HP:0002465). Evidence: TAS. (OMIM:300978)
- 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: IEA. (OMIM:300978)
- 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: IEA. (OMIM:300978)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 4/4. (PMID:25735484)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: IEA. (OMIM:300978)
- Excessive shyness (HP:0100962): Atypically high degree of awkwardness or apprehension experienced when approaching or being approached by others. Evidence: IEA. (OMIM:300978)
- Aggressive behavior (HP:0000718): Behavior or an act aimed at harming a person, animal, or physical property (e.g., acts of physical violence; shouting, swearing, and using harsh language; slashing someone's tires). Evidence: IEA. (OMIM:300978)
- 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: PCS. Frequency: 2/3. (PMID:25735484)
- Blue irides (HP:0000635): A markedly blue coloration of the iris. Evidence: PCS. Frequency: 1/3. (PMID:25735484)
- Decreased testicular size (HP:0008734): Reduced volume of the testicle (the male gonad). Evidence: IEA. (OMIM:300978)
- Pes planus (HP:0001763): A foot where the longitudinal arch of the foot is in contact with the ground or floor when the individual is standing; or, in a patient lying supine, a foot where the arch is in contact with the surface of a flat board pressed against the sole of the foot by the examiner with a pressure similar to that expected from weight bearing; or, the height of the arch is reduced. Evidence: IEA. (OMIM:300978)
- 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: PCS. Frequency: 4/4. (PMID:25735484)
- Downslanted palpebral fissures (HP:0000494): The palpebral fissure inclination is more than two standard deviations below the mean. Evidence: IEA. (OMIM:300978)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. (OMIM:300978)
- Micropenis (HP:0000054): Abnormally small penis. At birth, the normal penis is about 3 cm (stretched length from pubic tubercle to tip of penis) with micropenis less than 2.0-2.5 cm. Evidence: IEA. (OMIM:300978)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. Frequency: 2/3. (PMID:25735484)
- Global developmental delay (HP:0001263): A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age. Evidence: TAS. (OMIM:300978)
- X-linked recessive inheritance (HP:0001419): A mode of inheritance that is observed for recessive traits related to a gene encoded on the X chromosome. In the context of medical genetics, X-linked recessive disorders manifest in males (who have one copy of the X chromosome and are thus hemizygotes), but generally not in female heterozygotes who have one mutant and one normal allele. Evidence: PCS. (PMID:25735484)
- 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: 3/4. (PMID:25735484)
- Prominent nose (HP:0000448): Distance between subnasale and pronasale more than two standard deviations above the mean, or alternatively, an apparently increased anterior protrusion of the nasal tip. Evidence: TAS. (OMIM:300978)
- Hypotelorism (HP:0000601): Interpupillary distance less than 2 SD below the mean (alternatively, the appearance of an decreased interpupillary distance or closely spaced eyes). Evidence: IEA. (OMIM:300978)
- Convex nasal ridge (HP:0000444): Nasal ridge curving anteriorly to an imaginary line that connects the nasal root and tip. The nose appears often also prominent, and the columella low. Evidence: PCS. Frequency: 1/3. (PMID:25735484)
- Hypospadias (HP:0000047): Abnormal position of urethral meatus on the ventral penile shaft (underside) characterized by displacement of the urethral meatus from the tip of the glans penis to the ventral surface of the penis, scrotum, or perineum. Evidence: IEA. (OMIM:300978)
- Spasticity (HP:0001257): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: IEA. (OMIM:300978)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: IEA. (OMIM:300978)
- Widely spaced teeth (HP:0000687): Increased spaces (diastemata) between most of the teeth in the same dental arch. Evidence: PCS. Frequency: 1/3. (PMID:25735484)
- Velopharyngeal insufficiency (HP:0000220): Inability of velopharyngeal sphincter to sufficiently separate the nasal cavity from the oral cavity during speech. Evidence: IEA. (OMIM:300978)
- Small nail (HP:0001792): A nail that is diminished in length and width, i.e., underdeveloped nail. Evidence: IEA. (OMIM:300978)
- Pulmonary hypoplasia (HP:0002089). Evidence: IEA. Frequency: Very rare (HP:0040284). (OMIM:300978)
- Brachydactyly (HP:0001156): Digits that appear disproportionately short compared to the hand/foot. The word brachydactyly is used here to describe a series distinct patterns of shortened digits (brachydactyly types A-E). This is the sense used here. Evidence: IEA. (OMIM:300978)
- Anxiety (HP:0000739): Intense feelings of nervousness, tension, or panic often arise in response to interpersonal stresses. There is worry about the negative effects of past unpleasant experiences and future negative possibilities. Individuals may feel fearful, apprehensive, or threatened by uncertainty, and they may also have fears of falling apart or losing control. Evidence: IEA. (OMIM:300978)
- Broad forehead (HP:0000337): Width of the forehead or distance between the frontotemporales is more than two standard deviations above the mean (objective); or apparently increased distance between the two sides of the forehead. Evidence: PCS. Frequency: 3/3. (PMID:25735484)
- Abnormal heart morphology (HP:0001627): Any structural anomaly of the heart. Evidence: IEA. Frequency: Very rare (HP:0040284). (OMIM:300978)
- Downturned corners of mouth (HP:0002714): A morphological abnormality of the mouth in which the angle of the mouth is downturned. The oral commissures are positioned inferior to the midline labial fissure. Evidence: IEA. (OMIM:300978)
- Congenital diaphragmatic hernia (HP:0000776): The presence of a hernia of the diaphragm present at birth. Evidence: IEA. Frequency: Very rare (HP:0040284). (OMIM:300978)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: IEA. (OMIM:300978)
- Narrow face (HP:0000275): Bizygomatic (upper face) and bigonial (lower face) width are both more than 2 standard deviations below the mean (objective); or, an apparent reduction in the width of the upper and lower face (subjective). Evidence: IEA. (OMIM:300978)
- Broad-based gait (HP:0002136): An abnormal gait pattern in which persons stand and walk with their feet spaced widely apart. This is often a component of cerebellar ataxia. Evidence: IEA. (OMIM:300978)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: IEA. (OMIM:300978)
- Fine hair (HP:0002213): Hair that is fine or thin to the touch. Evidence: PCS. Frequency: 2/3. (PMID:25735484)
- 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. Frequency: 3/3. (PMID:25735484)
- Wide nasal bridge (HP:0000431): Increased breadth of the nasal bridge (and with it, the nasal root). Evidence: PCS. Frequency: 1/3. (PMID:25735484)
- Malar flattening (HP:0000272): Underdevelopment of the malar prominence of the jugal bone (zygomatic bone in mammals), appreciated in profile, frontal view, and/or by palpation. Evidence: IEA. (OMIM:300978)
- Broad thumb (HP:0011304): Increased thumb width without increased dorso-ventral dimension. Evidence: IEA. (OMIM:300978)
- Atypical behavior (HP:0000708): Atypical behavior is an abnormality in a person's actions that can be controlled or modulated by the will of the individual. While abnormal behaviors can be difficult to control, they are distinct from other abnormal actions that cannot be affected by the individual's will. Evidence: TAS. (OMIM:300978)
- Prominent nasal bridge (HP:0000426): Anterior positioning of the nasal root in comparison to the usual positioning for age. Evidence: IEA. (OMIM:300978)
- Self-injurious behavior (HP:0100716): Self-aggression. Evidence: IEA. (OMIM:300978)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: IEA. (OMIM:300978)
- Concave nail (HP:0001598): The natural longitudinal (posterodistal) convex arch is not present or is inverted. Evidence: PCS. Frequency: 1/3. (PMID:25735484)
- Cryptorchidism (HP:0000028): Testis in inguinal canal. That is, absence of one or both testes from the scrotum owing to failure of the testis or testes to descend through the inguinal canal to the scrotum. Evidence: TAS. (OMIM:300978)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: TAS. (OMIM:300978)
These phenotypes are associated with the disease intellectual disability, X-linked 61 (OMIM:300978).