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Mesomelic Dwarfism
Mesomelia refers to conditions in which the middle parts of limbs are disproportionately short. When applied to skeletal dysplasias, mesomelic dwarfism describes generalised shortening of the forearms and lower legs. This is in contrast to rhizomelic dwarfism in which the upper portions of limbs are short such as in achondroplasia. Forms of mesomelic dwarfism currently described include: * Langer mesomelic dysplasia * Ellis–van Creveld syndrome * Robinow syndrome * Léri–Weill dyschondrosteosis Léri–Weill dyschondrosteosis or LWD is a rare pseudoautosomal dominant genetic disorder which results in dwarfism with short forearms and legs ( mesomelic dwarfism) and a bayonet-like deformity of the forearms (Madelung's deformity). Causes It ... References Growth disorders {{congenital-malformation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dwarfism
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 , regardless of sex; the average adult height among people with dwarfism is , although some individuals with dwarfism are slightly taller. ''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 dependent upon the underlying condition. The most common and recognisable form of dwarfism in humans (comprising 70% of cases) is achondroplasia, a genetic disorder whereby the limbs are diminutive. Growth hormone deficiency is responsible for most other cases. Treatment depends on the underlying cause. Those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizomelia
Rhizomelia refers to either a disproportion of the length of the proximal limb, such as the shortened limbs of achondroplasia, or some other disorder of the hip or shoulder. According to Stedman's medical dictionary "rhizomelic" means "relating to hip or shoulder joints", while "micromelic" means "having disproportionately short or small limbs". Genetic skeletal dysplasias or Osteochondrodysplasia frequently lead to short stature, occasionally termed dwarfism, which is classified into proportionate and disproportionate short stature. Disproportionate short stature is further classified short-limb short stature and short-trunk short stature. In turn, short-limb short stature is classified into a) Rhizomelic, b) mesomelic and c) acromelic short stature. Rhizomelic short stature refers to skeletal dysplasias where the main shortening is due to involvement of the proximal limb segments i.e. femora and humeri. Typical examples of Rhizomelic short stature are achondroplasia and pseudoach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achondroplasia
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 for males and for females. Other features can include an enlarged head and prominent forehead. Complications can include sleep apnea or recurrent ear infections. Achondroplasia includes short-limb skeletal dysplasia with severe combined immunodeficiency. Achondroplasia is caused by a mutation in the fibroblast growth factor receptor 3 (''FGFR3'') gene that results in its protein being overactive. Achondroplasia results in impaired endochondral bone growth (bone growth within cartilage). The disorder has an autosomal dominant mode of inheritance, meaning only one mutated copy of the gene is required for the condition to occur. About 80% of cases occur in children of parents of average stature and resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Langer Mesomelic Dysplasia
Langer Mesomelic Dysplasia (LMD) is a rare congenital disorder characterized by an altered bone formation that causes a severe short and disproportionate stature. Signs and symptoms Clinically and radiologically, the disease is characterized by severe shortening of long bones (the limb's proximal and median segments are affected), aplasia or severe hypoplasia of the ulna and fibula, and a thickened and curved radius and tibia. These anomalies can cause deformities of the hands and feet. Hypoplasia of the mandible can also be present. Pathogenesis At the core of the disorder there is a homozygous or compound heterozygous mutation or deletion of the SHOX (Short Stature Homeobox), SHOXY (Short Stature Homeobox Y-linked) or PAR1 (where SHOX enhancer elements are located) genes, which is inherited in a pseudosomal recessive manner. Diagnosis Diagnosis may be suspected on the basis of the clinical and radiologic findings, and can supported by molecular analysis of the SHOX, SHOXY an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robinow Syndrome
Robinow syndrome is an extremely rare genetic disorder characterized by short-limbed dwarfism, abnormalities in the head, face, and external genitalia, as well as vertebral segmentation. The disorder was first described in 1969 by human geneticist Meinhard Robinow, along with physicians Frederic N. Silverman and Hugo D. Smith, in the ''American Journal of Diseases of Children''. By 2002, over 100 cases had been documented and introduced into medical literature. Two forms of the disorder exist, dominant and recessive, of which the former is more common. Patients with the dominant version often suffer moderately from the aforementioned symptoms. Recessive cases, on the other hand, are usually more physically marked, and individuals may exhibit more skeletal abnormalities.Robinow Syndrome Foundation. General Information'. Accessed 19 May 2006. The recessive form is particularly frequent in Turkey. However, this can likely be explained by a common ancestor, as these patients' fami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Léri–Weill Dyschondrosteosis
Léri–Weill dyschondrosteosis or LWD is a rare pseudoautosomal dominant genetic disorder which results in dwarfism with short forearms and legs ( mesomelic dwarfism) and a bayonet-like deformity of the forearms (Madelung's deformity). Causes It is caused by mutations in the short-stature homeobox gene found in the pseudoautosomal region PAR1 of the X and Y chromosomes, at band Xp22.33 or Yp11.32. SHOX gene deletions have been identified as the major cause of Leri–Weill syndrome. Leri–Weill dyschondrosteosis is characterized by mesomelic short stature, with bowing of the radius more so than the ulna in the forearms and bowing of the tibia while sparing the fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity .... Diagnosis Diagnosis is made following genetic blood testing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
