A reduction in the level of performance of the kidneys in areas of function comprising the concentration of urine, removal of wastes, the maintenance of electrolyte balance, homeostasis of blood pressure, and calcium metabolism.

Coxa valga is a deformity of the hip in which the angle between the femoral shaft and the femoral neck is increased compared to age-adjusted values (about 150 degrees in newborns gradually reducing to 120-130 degrees in adults).

A partial dislocation of the hip joint, whereby the head of the femur is partially displaced from the socket.

The legs angle inward, such that the knees are close together and the ankles far apart.

Short, hypoplastic middle phalanx of finger, affecting all fingers.

Sclerosis of the epiphyses of the phalanges of the fingers, leading to an increased degree of radiopacity (white or ivory appearance) in X-rays.

Underdevelopment of one or more carpal bones.

Carpal bones with irregular or fragmented margins.

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).

Abnormally increased size of the liver.

Reduced number of beta cells in the pancreatic islets of Langerhans.

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.

Displacement of the femur from its normal location in the hip joint.

Abnormally increased curvature (anterior concavity) of the lumbar or cervical spine.

A rare group of primary bone dysplasia disorders characterized by the association of epiphyseal anomalies of long bones causing joint pain early in life, recurrent osteochondritis and early arthrosis. This group contains an heterogeneous group of diseases with variable expression. Common reported clinical signs include waddling gait and pain at onset, and moderate short stature. Some forms are mainly limited to the femoral epiphyses, while several other syndromes are characterized by the association of multiple epiphyseal dysplasia with other clinical manifestations such as myopia, deafness and facial dysmorphism. Diagnosis relies on identification of the radiological features.

A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move.

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).

A rounded, bulging chest that resembles the shape of a barrel. That is, there is an increased anteroposterior diameter and usually some degree of kyphosis.

Decreased width of the wing (or ala) of the ilium (which is the large expanded portion which bounds the greater pelvis laterally).

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

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

The odontoid process, or dens, is a bony projection from the axis (C2) upward into the ring of the atlas (C1) at the top of the spine. During embryogenesis, the body of the odontoid derives from the centrum of the atlas and separates from the atlas, fusing with the superior portion of the axis. If the odontoid is hypoplastic or absent, the attachments for the apical and alar ligaments are missing, allowing for excessive rotation of the atlas, craniocervical instability, and possibly cord compression (summary by Stevens et al., 2009).

Reduction in the size or volume of epiphyses.

Abnormal flatness (decreased height) of epiphyses.

A cone-shaped appearance of the epiphyses of the fingers of the hand, producing a 'ball-in-a-socket' appearance. The related entity 'angel-shaped' epiphysis refers to a pronounced cone-shaped epiphysis in combination with a pseudoepiphysis at the distal end of a phalanx.

Defective ossification in an irregular pattern of the seven bones of the foot comprising the calcaneus, talus, cuboid, navicular, and the cuneiform bones.

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

Type 1 diabetes mellitus (T1D), also designated insulin-dependent diabetes mellitus (IDDM), is a disorder of glucose homeostasis characterized by susceptibility to ketoacidosis in the absence of insulin therapy. It is a genetically heterogeneous autoimmune disease affecting about 0.3% of Caucasian populations (Todd, 1990). Genetic studies of T1D have focused on the identification of loci associated with increased susceptibility to this multifactorial phenotype. The classic phenotype of diabetes mellitus is polydipsia, polyphagia, and polyuria which result from hyperglycemia-induced osmotic diuresis and secondary thirst. These derangements result in long-term complications that affect the eyes, kidneys, nerves, and blood vessels.

A type of diabetes mellitus related not to lack of insulin but rather to lack of response to insulin on the part of the target tissues of insulin such as muscle, fat, and liver cells. This type of diabetes is typically associated with increases both in blood glucose concentrations as well as in fasting and postprandial serum insulin levels.

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).

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.

Posterior positioning of the nasal root in relation to the overall facial profile for age.

Small indentation anterior to the insertion of the ear.

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).