Joint pain.

For children from birth to 4 years of age the palm width is more than 2 SD above the mean; for children from 4 to 16 years of age the palm width is above the 95th centile; or, the width of the palm appears disproportionately wide for the length.

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

Diminished length of one or more metacarpal bones in relation to the others of the same hand or to the contralateral metacarpal.

Arm shortening because of underdevelopment of one or more bones of the upper extremity.

Short palm.

An abnormally wide femoral neck (which is the process of bone, connecting the femoral head with the femoral shaft).

Diminished length of a metatarsal bone, with resultant proximal displacement of the associated toe.

A foot for which the measured width is above the 95th centile for age; or, a foot that appears disproportionately wide for its length.

Limited ability to straighten the arm at the elbow joint.

Coxa vara includes all forms of decrease of the femoral neck shaft angle (the angle between the neck and the shaft of the femur) to less than 120 degrees.

Weakness of the hip girdle and upper thigh muscles, for instance in myopathies, leads to an instability of the pelvis on standing and walking. If the muscles extending the hip joint are affected, the posture in that joint becomes flexed and lumbar lordosis increases. The patients usually have difficulties standing up from a sitting position. Due to weakness in the gluteus medius muscle, the hip on the side of the swinging leg drops with each step (referred to as Trendelenburg sign). The gait appears waddling. The patients frequently attempt to counteract the dropping of the hip on the swinging side by bending the trunk towards the side which is in the stance phase (in the German language literature this is referred to as Duchenne sign). Similar gait patterns can be caused by orthopedic conditions when the origin and the insertion site of the gluteus medius muscle are closer to each other than normal, for instance due to a posttraumatic elevation of the trochanter or pseudarthrosis of the femoral neck.

Osteoarthritis (OA) is a degenerative disease of the joints characterized by degradation of the hyaline articular cartilage and remodeling of the subchondral bone with sclerosis (Meulenbelt et al., 2006). Clinical problems include pain and joint stiffness often leading to significant disability and joint replacement. Osteoarthritis exhibits a clear predilection for specific joints; it appears most commonly in the hip and knee joints and lumbar and cervical spine, as well as in the distal interphalangeal and the first carpometacarpal (base of thumb) and proximal interphalangeal joints of the hand; however, patients with osteoarthritis may have 1, a few, or all of these sites affected (Stefansson et al., 2003). According to a conservative estimate, greater than 70% of the population of the United States at age 65 years is affected by the disease, reflecting its age dependence. Genetic Heterogeneity of Susceptibility to Osteoarthritis Susceptibility to osteoarthritis has been associated with variation in other genes: OS2 (140600) with variation in the MATN3 gene (602109) on chromosome 2p24; OS3 (607850) with variation in the ASPN gene (608135) on chromosome 9q22; and OS5 (612400) with variation in the GDF5 gene (601146) on chromosome 20q11. Other susceptibility loci for osteoarthritis have been mapped to chromosomes 2q33 (OS4; 610839) and 3p24 (OS6; 612401).

A deformity of the chest caused by overgrowth of the ribs and characterized by protrusion of the sternum.

An osteochondrodysplasia that results in abnormalities of bone growth in the vertebral column, epiphysis, and metaphysis.

An abnormal accentuation of the inward curvature of the spine in the lumbar region.

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

A type of disproportionate short stature characterized by a short trunk but a average-sized limbs.

Abnormally increased size of the costochondral junctions, which are located between the distal part of the ribs and the costal cartilages, which are bars of hyaline cartilage that connect the ribs to the sternum.

The presence of dysplastic regions in metaphyseal regions.