Achondroplasia is a genetic disorder with an autosomal dominant pattern of inheritance whose primary feature is dwarfism. In those with the condition, the arms and legs are short, while the torso is typically of normal length. Those affected have an average adult height of 131 centimetres for males and 123 centimetres (4 ft) for females. Other features can include an enlarged head and prominent forehead. Complications can include sleep apnea or recurrent ear infections. Achondroplasia includes the extremely rare short-limb skeletal dysplasia with severe combined immunodeficiency.
Dwarfism is a condition wherein an organism is exceptionally small, and mostly occurs in the animal kingdom. In humans, it is sometimes defined as an adult height of less than 147 centimetres, regardless of sex; the average adult height among people with dwarfism is 120 centimetres (4 ft). Disproportionate dwarfism is characterized by either short limbs or a short torso. In cases of proportionate dwarfism, both the limbs and torso are unusually small. Intelligence is usually normal, and most have a nearly normal life expectancy. People with dwarfism can usually bear children, though there are additional risks to the mother and child depending upon the underlying condition.
Crouzon syndrome is an autosomal dominant genetic disorder known as a branchial arch syndrome. Specifically, this syndrome affects the first branchial arch, which is the precursor of the maxilla and mandible. Since the branchial arches are important developmental features in a growing embryo, disturbances in their development create lasting and widespread effects.
Diastrophic dysplasia is an autosomal recessive dysplasia which affects cartilage and bone development. Diastrophic dysplasia is due to mutations in the SLC26A2 gene.
Atelosteogenesis, type II is a severe disorder of cartilage and bone development. It is rare, and infants with the disorder are usually stillborn; those who survive birth die soon after.
Thanatophoric dysplasia is a severe skeletal disorder characterized by a disproportionately small ribcage, extremely short limbs and folds of extra skin on the arms and legs.
Mitochondrial trifunctional protein deficiency is an autosomal recessive fatty acid oxidation disorder that prevents the body from converting certain fats to energy, particularly during periods without food. People with this disorder have inadequate levels of an enzyme that breaks down a certain group of fats called long-chain fatty acids.
Spondyloperipheral dysplasia is an autosomal dominant disorder of bone growth. The condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly). Some affected individuals also have other skeletal abnormalities, short stature, nearsightedness (myopia), hearing loss, and mental retardation. Spondyloperipheral dysplasia is a subtype of collagenopathy, types II and XI.
Spondyloepiphyseal dysplasia congenita is a rare disorder of bone growth that results in dwarfism, characteristic skeletal abnormalities, and occasionally problems with vision and hearing. The name of the condition indicates that it affects the bones of the spine (spondylo-) and the ends of bones (epiphyses), and that it is present from birth (congenital). The signs and symptoms of spondyloepiphyseal dysplasia congenita are similar to, but milder than, the related skeletal disorders achondrogenesis type 2 and hypochondrogenesis. Spondyloepiphyseal dysplasia congenita is a subtype of collagenopathy, types II and XI.
Crouzonodermoskeletal syndrome is a disorder characterized by the premature joining of certain bones of the skull (craniosynostosis) during development and a skin condition called acanthosis nigricans.
Jackson–Weiss syndrome (JWS) is a genetic disorder characterized by foot abnormalities and the premature fusion of certain bones of the skull (craniosynostosis), which prevents further growth of the skull and affects the shape of the head and face. This genetic disorder can also sometimes cause intellectual disability and crossed eyes. It was characterized in 1976.
Autosomal recessive multiple epiphyseal dysplasia (ARMED), also called epiphyseal dysplasia, multiple, 4 (EDM4), multiple epiphyseal dysplasia with clubfoot or –with bilayered patellae, is an autosomal recessive congenital disorder affecting cartilage and bone development. The disorder has relatively mild signs and symptoms, including joint pain, scoliosis, and malformations of the hands, feet, and knees.
TNF receptor associated periodic syndrome (TRAPS) is a periodic fever syndrome associated with mutations in a receptor for the molecule tumor necrosis factor (TNF) that is inheritable in an autosomal dominant manner. Individuals with TRAPS have episodic symptoms such as recurrent high fevers, rash, abdominal pain, joint/muscle aches and puffy eyes.
Pseudoachondroplasia is an inherited disorder of bone growth. It is a genetic autosomal dominant disorder. It is generally not discovered until 2–3 years of age, since growth is normal at first. Pseudoachondroplasia is usually first detected by a drop of linear growth in contrast to peers, a waddling gait or arising lower limb deformities.
Fibroblast growth factor receptor 3 is a protein that in humans is encoded by the FGFR3 gene. FGFR3 has also been designated as CD333. The gene, which is located on chromosome 4, location p16.3, is expressed in tissues such as the cartilage, brain, intestine, and kidneys.
Cantú syndrome is a rare condition characterized by hypertrichosis, osteochondrodysplasia, and cardiomegaly. Less than 50 cases have been described in the literature; they are associated with a mutation in the ABCC9-gene that codes for the ABCC9-protein.
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.
Severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN) is a very rare genetic disorder. This disorder is one that affects bone growth and is characterized by skeletal, brain, and skin abnormalities. Those affected by the disorder are severely short in height and commonly possess shorter arms and legs. In addition, the bones of the legs are often bowed and the affected have smaller chests with shorter rib bones, along with curved collarbones. Other symptoms of the disorder include broad fingers and extra folds of skin on the arms and legs. Developmentally, many individuals who suffer from the disorder show a higher level in delays and disability. Seizures are also common due to structural abnormalities of the brain. Those affected may also suffer with apnea, the slowing or loss of breath for short periods of time.
Schneckenbecken dysplasia is a rare pre-natally fatal hereditary autosomal recessive condition which affects the bones and pre-natal growth.
Spondyloenchondrodysplasia is the medical term for a rare spectrum of symptoms that are inherited following an autosomal recessive inheritance pattern. Skeletal anomalies are the usual symptoms of the disorder, although its phenotypical nature is highly variable among patients with the condition, including symptoms such as muscle spasticity or thrombocytopenia purpura. It is a type of immunoosseous dysplasia.
