A bending or abnormal curvature of the tibia.

A severe degree of short stature, more than -4 SD from the mean corrected for age and sex.

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

Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.

The repeated occurrence of bone fractures (implying an abnormally increased tendency for fracture).

Osteopenia is a term to define bone density that is not normal but also not as low as osteoporosis. By definition from the World Health Organization osteopenia is defined by bone densitometry as a T score -1 to -2.5.

Osteoporosis is a systemic skeletal disease characterized by low bone density and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility. According to the WHO criteria, osteoporosis is defined as a BMD that lies 2.5 standard deviations or more below the average value for young healthy adults (a T-score below -2.5 SD).

Abnormally small dimension of the Maxilla. Usually creating a malocclusion or malalignment between the upper and lower teeth or resulting in a deficient amount of projection of the base of the nose and lower midface region.

An abnormal curvature of the spine in both a coronal (lateral) and sagittal (back-to-front) plane.

The distal interphalangeal joint and/or the proximal interphalangeal joint of the fingers or toes cannot be extended to 180 degrees by either active or passive extension.

An abnormally increased tendency to fractures of bones caused by an abnormal reduction in bone strength that is generally associated with an increased risk of fracture.

An irregular surface of the vertebral end plates, which are normally relatively smooth.

The ability of the finger joints to move beyond their normal range of motion.

A flattened vertebral body shape with reduced distance between the vertebral endplates.

Exaggerated concavity of the anterior or posterior surface of the vertebral body, i.e., the upper and lower vertebral endplates are hollowed inward.

Anterior tongue-like protrusions of the vertebral bodies.

Underdevelopment of the malar prominence of the jugal bone (zygomatic bone in mammals), appreciated in profile, frontal view, and/or by palpation.

Bowing (abnormal curvature) of the femur.

The presence of extra bones within a cranial suture. Wormian bones are irregular isolated bones which appear in addition to the usual centers of ossification of the cranium.

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

An increased susceptibility to lower respiratory tract infections as manifested by a history of recurrent lower respiratory tract infections.

Inflammation of the periodontium.

Glycosylated transferrin concentrations can be measured in serum as a marker of N-linked glycosylation fidelity. 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. These terms are retained for historical reasons but for new annotations the precise glycosylation defect should be recorded.

Any abnormality of the teeth.

Abnormal prominence of the chin related to increased length of the mandible.

The palpebral fissure inclination is more than two standard deviations below the mean.

Wrinkled, redundant, inelastic and sagging skin.

The presence of an increased degree of wrinkling (irregular folds and indentations) of the skin as compared with age-related norms.

An abnormality of the hair.

A degree of wrinkling of the facial skin that is more than expected for the age of the individual, leading to a prematurely aged appearance.

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).

An eye that is more deeply recessed into the plane of the face than is typical.