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).

A deficiency or slowing down of growth pre- and postnatally.

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Infrequent or difficult evacuation of feces.

Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.

A series of rhythmic and involuntary muscle contractions (at a frequency of about 5 to 7 Hz) that occur in response to an abruptly applied and sustained stretch.

A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes.

A seizure is an intermittent abnormality of nervous system physiology characterised by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

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

An abnormality of the cerebral white matter.

Delayed myelination.

Complete lack of development of speech and language abilities.

Ocular motor apraxia is a deficiency in voluntary, horizontal, lateral, fast eye movements (saccades) with retention of slow pursuit movements. The inability to follow objects visually is often compensated by head movements. There may be decreased smooth pursuit, and cancellation of the vestibulo-ocular reflex.

Subnormal intellectual functioning which originates during the developmental period. Intellectual disability, previously referred to as mental retardation, has been defined as an IQ score below 70.

A type of kinetic tremor that occurs during target directed movement is called intention tremor. That is, an oscillatory cerebellar ataxia that tends to be absent when the limbs are inactive and during the first part of voluntary movement but worsening as the movement continues and greater precision is required (e.g., in touching a target such as the patient's nose or a physician's finger).

A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints.

Difficulty to maintain correct position of the head while standing or sitting.

Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.

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

An abnormal morphology (form) of the face or its components.

An abnormality in voluntary or involuntary eye movements or their control.