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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 pseudoacho ... [...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. It is the most common cause of dwarfism and affects about 1 in 27,500 people. In those with the condition, the Rhizomelia, 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 Macrocephaly, enlarged head with Skull bossing, prominent forehead (frontal bossing) and underdevelopment of the midface (midface hypoplasia). Complications can include sleep apnea or recurrent ear infections. Achondroplasia includes the extremely rare 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 Gain-of-function, overactive. Achondroplasia results in impaired endochondral bone growth (bone growth within car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteochondrodysplasia
An osteochondrodysplasia,Etymology: . or skeletal dysplasia, is a disorder of the development of bone and cartilage. Osteochondrodysplasias are rare diseases. About 1 in 5,000 babies are born with some type of skeletal dysplasia. Nonetheless, if taken collectively, genetic skeletal dysplasias or osteochondrodysplasias comprise a recognizable group of genetically determined disorders with generalized skeletal affection. These disorders lead to disproportionate short stature and bone abnormalities, particularly in the arms, legs, and spine. Skeletal dysplasia can result in marked functional limitation and even mortality. Osteochondrodysplasias or skeletal dysplasia subtypes can overlap in clinical aspects, therefore plain radiography is absolutely necessary to establish an accurate diagnosis. Magnetic resonance imaging can provide further diagnostic insights and guide treatment strategies especially in cases of spinal involvement. As some disorders that cause skeletal dysplasia have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoachondroplasia
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. Pseudoachondroplasia (also known as PSACH, pseudoachondroplastic dysplasia, and pseudoachondroplastic spondyloepiphyseal dysplasia syndrome) is an osteochondrodysplasia that results in mild to severely short stature due to the inhibition of skeletal growth primarily in the limbs. Though similarities in nomenclature may cause confusion, pseudoachondroplasia should not be confused with achondroplasia, which is a clinically and genetically distinct skeletal dysplasia. Pseudoachondroplasia is caused by a heterozygous mutation in the gene encoding cartilage oligomeric matrix protein (COMP). Mutation in the COMP gene can also cause multiple epi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amelia (birth Defect)
Amelia is the birth defect of lacking one or more limbs. The term may be modified to indicate the number of legs or arms missing at birth, such as tetra-amelia for the absence of all four limbs. The term is . Symptoms The diagnosis of amelia syndrome is established clinically and can be made on routine prenatal ultrasonography. WNT3 is the only gene known to be associated with tetra-amelia syndrome. Molecular genetic testing on a clinical basis can be used to diagnose the incidence of the syndrome. The mutation detection frequency is unknown as only a limited number of families have been studied. Affected infants are often stillborn or die shortly after birth. Description Amelia may be present as an isolated defect, but it is often associated with major malformations in other organ systems. These frequently include cleft lip and/or palate, body wall defects, malformed head, and defects of the neural tube, kidneys, and diaphragm. Facial clefts may be accompanied by other faci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizomelic Chondrodysplasia Punctata
Rhizomelic chondrodysplasia punctata is a rare developmental brain disorder characterized by abnormally short arms and legs (''rhizomelia''), seizures, recurrent respiratory tract infections and congenital cataracts. The cause is a genetic mutation that results in low levels of plasmalogens, which are a type of lipid found in cell membranes throughout the body, but whose function is not known. Signs and symptoms Rhizomelic chondrodysplasia punctata has the following symptoms: * Bilateral shortening of the femur, resulting in short legs * Post-natal growth problems (deficiency) * Cataracts * Intellectual disability * Possible seizures * Possible infections of respiratory tract Genetics This condition is a consequence of mutations in the '' PEX7'' gene, the '' GNPAT'' gene (which is located on chromosome 1) or the '' AGPS'' gene. The condition is acquired in an autosomal recessive manner. Pathophysiology The mechanism of rhizomelic chondrodysplasia punctata in the case of type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
