Abnormally increased frequency (usually defined as three or more) loose or watery bowel movements a day.

An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk.

A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.

Abnormally increased size of the liver.

Deficiency of thyroid hormone.

Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Severe mental retardation is defined as an intelligence quotient (IQ) in the range of 20-34.

A cataract is an opacity or clouding that develops in the crystalline lens of the eye or in its capsule.

Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles.

Anemia caused by low iron intake, inefficient iron absorption in the gastrointestinal tract, or chronic blood loss.

Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.

A coloboma of the iris.

Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).

Increased time to coagulation in the partial thromboplastin time (PTT) test, a measure of the intrinsic and common coagulation pathways. Phospholipid, and activator, and calcium are mixed into an anticoagulated plasma sample, and the time is measured until a thrombus forms.

The presence of nipples that instead of pointing outward are retracted inwards.

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).

The palpebral fissure inclination is more than two standard deviations above the mean for age (objective); or, the inclination of the palpebral fissure is greater than typical for age.

A degree of language development that is significantly below the norm for a child of a specified age.

Epicanthus is a condition in which a fold of skin stretches from the upper to the lower eyelid, partially covering the inner canthus. Usher (1935) noted that epicanthus is a normal finding in the fetus of all races. Epicanthus also occurs in association with hereditary ptosis (110100).

Hypsarrhythmia is abnormal interictal high amplitude waves and a background of irregular spikes. There is continuous (during wakefulness), high-amplitude (>200 Hz), generalized polymorphic slowing with no organized background and multifocal spikes demonstrated by electroencephalography (EEG).

A reduced frequency or duration of eye contact.

A sudden flexion, extension, or mixed extension-flexion of predominantly proximal and truncal muscles that is usually more sustained than a myoclonic movement but not as sustained as a tonic seizure. Limited forms may occur

A severe delay in the achievement of motor or mental milestones in the domains of development of a child.

Abnormal transferrin isoform profile consistent with a type I congenital disorder of glycosylation. In the traditional nomenclature for congenital disorders of glycosylation, absence of entire glycans was designated type I, and loss of one or more monosaccharides as type II.

The capability that a joint (or a group of joints) has to move, passively and/or actively, beyond normal limits along physiological axes.

Increased breadth of the nasal bridge (and with it, the nasal root).

Absence of concavity or convexity of the face when viewed in profile.

Increased dimensions of the Virchow-Robin spaces (also known as perivascular spaces), which surround the walls of vessels as they course from the subarachnoid space through the brain parenchyma. Perivascular spaces are commonly microscopic, and not visible on conventional neuroimaging. This term refers to an increase of size of these spaces such that they are visible on neuroimaging (usually magnetic resonance imaging). The dilatations are regular cavities that always contain a patent artery.

A type of Developmental delay characterized by a delay in acquiring motor skills.

Generalized muscular hypotonia (abnormally low muscle tone).

An increase in size of the ventricular system of the brain.

Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery.

The condition of inability to eat normally treated by placement of a thin tube through the nose into the stomach that is then used to carry food.

Infantile spasms represent a subset of "epileptic spasms". Infantile Spasms are epileptic spasms starting in the first year of life (infancy).

Delayed myelination in the central nervous system.

A lighter than expected T2 signal on magnetic resonance imaging (MRI) of the basal ganglia. This term refers to a localized hyperintensity affecting a particular region of the basal ganglia.

Decreased activity of coagulation factor XI. Factor XI, also known as plasma thromboplastin antecedent, is a serine proteinase that activates factor IX.

A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter.

Head circumference below 2 standard deviations below the mean for age and gender.

A manifest or latent ocular deviation in which one or both eyes tends to deviate nasally.

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).

Abnormally low body weight.