|Other names||Acromesomelic dwarfism |
Acromesomelic dysplasia is a rare skeletal disorder that causes abnormal bone and cartilage development, leading to shortening of the forearms, lower legs, hands, feet, fingers, and toes. Five different genetic mutations have been implicated in the disorder. Treatment is individualized but is generally aimed at palliating symptoms, for example, treatment of kyphosis and lumbar hyperlordosis.
Acromesomelic dysplasia describes a group of extremely rare, inherited, progressive skeletal conditions that result in a particular form of short stature, called short-limb dwarfism.
Acromesomelic dysplasia is inherited as an autosomal recessive trait.
There are different types of acromesomelic dysplasia, which are distinguished by their genetic cause.
- Acromesomelic dysplasia, Maroteaux type
- Acromesomelic dysplasia, Hunter-Thompson type
- Acromesomelic dysplasia, Grebe type
Signs and symptoms
Affected infants often have a normal birth weight. In most cases, in addition to having unusually short, broad hands and feet, affected infants often have characteristic facial abnormalities that are apparent at birth. Such features may include a relatively enlarged head, unusually prominent forehead, pronounced back portion of the head (occipital prominence), a slightly flattened midface, and/or an abnormally small, pug nose. During the first years of life, as the forearms, lower legs, hands, and feet do not grow proportionally with the rest of the body, short stature (short-limb dwarfism) begins to become apparent. Over time, affected individuals may be unable to fully extend the arms, rotate the arms inward toward the body with the palms facing down, or rotate the arms outward with the palms facing upward. In some cases, affected individuals may also experience progressive degeneration, stiffness, tenderness, and pain of the elbows (osteoarthritis). Abnormalities of cartilage and bone development may also cause the bones within the fingers, toes, hands, and feet to become increasingly shorter and broader during the first years of life. During the second year of life, the growing ends of these bones may begin to appear abnormally shaped like a cone or a square and may fuse prematurely. This causes the fingers and toes to appear short and stubby. The hands and feet may seem unusually short, broad, and square; and the feet may appear abnormally flat. In early childhood, extra, loose skin may also develop over the fingers. During early childhood, affected individuals may also begin to experience progressive, abnormal curvature of the spine. In rare cases, affected individuals can experience delayed puberty and corneal clouding.