A form of malignant cancer of the connective tissue surrounding nerves. Given its origin and behavior, it is classified as a sarcoma.

Increased back to front length of the foot.

The presence of an unusually high plantar arch. Also called high instep, pes cavus refers to a distinctly hollow form of the sole of the foot when it is bearing weight.

Any structural anomaly of the heart and great vessels.

Any structural anomaly of the heart.

A height above that which is expected according to age and gender norms.

Excessive postnatal growth which may comprise increased weight, increased length, and/or increased head circumference.

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 decreased magnitude of the sensory perception of sound.

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.

The presence of multiple cutaneous neurofibromas.

A neurofibroma in which Schwann cells proliferate inside the nerve sheath, producing an irregularly thickened, distorted, tortuous structure.

Reduced attention span characterized by distractibility and impulsivity but not necessarily satisfying the diagnostic criteria for attention deficit hyperactivity disorder.

Abnormal cognition with deficits in thinking, reasoning, or remembering.

A glioma originating in the optic nerve or optic chiasm.

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

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.

Attention deficit-hyperactivity disorder (ADHD) is the most common childhood-onset behavioral disorder, affecting approximately 5 to 10% of children and adolescents (Wolraich et al., 1996). In this condition, persistent inattention and/or hyperactive-impulsive behavior results in impaired social and/or academic functioning. Boys are affected about 8 times more frequently than girls (Zametkin et al., 1990). Genetic Heterogeneity of Attention Deficit-Hyperactivity Disorder Susceptibility to ADHD7 (607478) may be conferred by variation in the TPH2 gene (607478) on chromosome 12q21. ADHD8 (619957) is caused by mutation in the CDH2 gene (114020) on chromosome 18q12. Several loci for susceptibility to ADHD have been mapped, including ADHD1 (608903) on chromosome 16p13, ADHD2 (608904) on chromosome 17p11, ADHD3 (608905) on chromosome 6q12, ADHD4 (608906) on chromosome 5p13, ADHD5 (612311) on 2q21.1, and ADHD6 (612312) on 13q12.11. Also see MOLECULAR GENETICS.

The presence of Neurofibromas in the subcutis.

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 structural abnormality of the central nervous system.

Neurofibromas originating in the spine.

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.

Impairment of certain skills such as reading or writing, coordination, self-control, or attention that interfere with the ability to learn. The impairment is not related to a global deficiency of intelligence.

A fluid filled cavity that develops with a bone.

Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.

The presence of an abnormal lateral curvature of the spine.

The ability of a joint to move beyond its normal range of motion.

Generalized muscular hypotonia (abnormally low muscle tone).

A defect of the chest wall characterized by a depression of the sternum, giving the chest ("pectus") a caved-in ("excavatum") appearance.

Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.

An abnormal difference between the left and right sides of the face.

Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues.

Increased side-to-side width of the neck.

Cafe-au-lait spots are hyperpigmented lesions that can vary in color from light brown to dark brown with smooth borders and having a size of 1.5 cm or more in adults and 0.5 cm or more in children.

The presence in the inguinal region (groin) of an increased number of freckles, small circular spots on the skin that are darker than the surrounding skin because of deposits of melanin.

The presence in the axillary region (armpit) of an increased number of freckles, small circular spots on the skin that are darker than the surrounding skin because of deposits of melanin.

Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (see 300000), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).

A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error.

The presence of pigmented, oval and dome-shaped raised hamartomatous nevi of the iris..