SADDAN
Encyclopedia
SADDAN is a rare inherited disorder of bone
growth characterized by skeletal, brain
, and skin
abnormalities.
All people with this condition are extremely short with particularly short arms and legs. Other signs and symptoms include unusual bowing of the leg bones; a small chest with short ribs and curved collar bones; short, broad fingers; and folds of extra skin on the arms and legs. Structural abnormalities of the brain lead to seizures, profound developmental delay, and mental retardation. Acanthosis nigricans
, a progressive skin disorder characterized by thick, dark, velvety skin, develops in infancy or early childhood. People with SADDAN often live into childhood and adulthood.
Many of the features of SADDAN are similar to those seen in other skeletal disorders, specifically achondroplasia
and thanatophoric dysplasia
.
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
growth characterized by skeletal, brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
, and skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
abnormalities.
All people with this condition are extremely short with particularly short arms and legs. Other signs and symptoms include unusual bowing of the leg bones; a small chest with short ribs and curved collar bones; short, broad fingers; and folds of extra skin on the arms and legs. Structural abnormalities of the brain lead to seizures, profound developmental delay, and mental retardation. Acanthosis nigricans
Acanthosis nigricans
Acanthosis nigricans is a brown to black, poorly defined, velvety hyperpigmentation of the skin. It is usually found in body folds, such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas.-Causes:...
, a progressive skin disorder characterized by thick, dark, velvety skin, develops in infancy or early childhood. People with SADDAN often live into childhood and adulthood.
Many of the features of SADDAN are similar to those seen in other skeletal disorders, specifically achondroplasia
Achondroplasia
Achondroplasia dwarfism occurs as a sporadic mutation in approximately 85% of cases or may be inherited in an autosomal dominant genetic disorder that is a common cause of dwarfism...
and thanatophoric dysplasia
Thanatophoric dysplasia
Thanatophoric dysplasia is a severe skeletal disorder characterized by extremely short limbs and folds of extra skin on the arms and legs.-Symptoms:Infants with this condition have disproportionately short arms and legs with extra folds of skin...
.