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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] |
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] |
FGFR3
Fibroblast growth factor receptor 3 is a protein that in humans is encoded by the ''FGFR3'' gene. FGFR3 has also been designated as CD333 (cluster of differentiation 333). The gene, which is located on chromosome 4, location q16.3, is expressed in tissues such as the cartilage, brain, intestine, and kidneys. The FGFR3 gene produces various forms of the FGFR3 protein; the location varies depending on the isoform of the FGFR3 protein. Since the different forms are found within different tissues the protein is responsible for multiple growth factor interactions. Gain of function mutations in FGFR3 inhibits chondrocyte proliferation and underlies achondroplasia and hypochondroplasia. Function The protein encoded by this gene is a member of the fibroblast growth factor receptor family, where amino acid sequence is highly conserved between members and throughout evolution. FGFR family members differ from one another in their ligand affinities and tissue distribution. A full-length r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibroblast Growth Factor Receptor 3
Fibroblast growth factor receptor 3 is a protein that in humans is encoded by the ''FGFR3'' gene. FGFR3 has also been designated as CD333 (cluster of differentiation 333). The gene, which is located on chromosome 4, location q16.3, is expressed in tissues such as the cartilage, brain, intestine, and kidneys. The FGFR3 gene produces various forms of the FGFR3 protein; the location varies depending on the isoform of the FGFR3 protein. Since the different forms are found within different tissues the protein is responsible for multiple growth factor interactions. Gain of function mutations in FGFR3 inhibits chondrocyte proliferation and underlies achondroplasia and hypochondroplasia. Function The protein encoded by this gene is a member of the fibroblast growth factor receptor family, where amino acid sequence is highly conserved between members and throughout evolution. FGFR family members differ from one another in their ligand affinities and tissue distribution. A full-length r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short-limb Skeletal Dysplasia With Severe Combined Immunodeficiency
Short-limb skeletal dysplasia with severe combined immunodeficiency is an extremely rare autosomal recessive type of achondroplasia which is characterized by short stature, bowing of the long bones, and generalized metaphyseal abnormalities alongside signs of SCID such as recurrent severe infections, failure to thrive, chronic diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ..., and a notable absence of T and B lymphocytes. Around 11 cases have been described in medical literature. References {{reflist Cell surface receptor deficiencies Connective tissue diseases Growth disorders Rare diseases Immunodeficiency Genetic diseases and disorders Autosomal recessive disorders ... [...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 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull Bossing
Skull bossing is a descriptive term in medical physical examination indicating a protuberance of the skull, most often in the frontal bones of the forehead ("frontal bossing"). Although prominence of the skull bones may be normal, skull bossing may be associated with certain medical conditions, including nutritional, metabolic, hormonal, and hematologic disorders. Frontal bossing Frontal bossing is the development of an unusually pronounced forehead which may also be associated with a heavier than normal brow ridge. It is caused by enlargement of the frontal bone, often in conjunction with abnormal enlargement of other facial bones, skull, mandible, and bones of the hands and feet. Frontal bossing may be seen in a few rare medical syndromes such as acromegaly – a chronic medical disorder in which the anterior pituitary gland produces excess growth hormone (GH). Frontal bossing may also occur in diseases resulting in chronic anemia, where there is increased hematopoiesis and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypochondroplasia
Hypochondroplasia (HCH) is a developmental disorder caused by an autosomal dominant genetic defect in the fibroblast growth factor receptor 3 gene ('' FGFR3'') that results in a disproportionately short stature, micromeliaupdate 2013 and a head that appears large in comparison with the underdeveloped portions of the body. It is classified as short-limbed dwarfism. Signs and symptoms Individuals affected by this disorder appear normal at birth. As the infant grows, however, their arms and legs do not develop properly, and their body becomes thicker and shorter than normal. The following are characteristics consistent with this condition: * Brachydactyly * Short stature * Micromelia * Skeletal dysplasia * Abnormality of femur Cause Hypochondroplasia is transmitted as an autosomal dominant trait affecting the ''FGFR3'' gene on chromosome 4p16.3. There is currently no cure for this condition. Pathophysiology This disorder results from mutations in the proximal tyrosine kinas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lordosis
Lordosis is historically defined as an ''abnormal'' inward curvature of the lumbar spine. However, the terms ''lordosis'' and ''lordotic'' are also used to refer to the normal inward curvature of the lumbar and cervical regions of the human spine. Similarly, kyphosis historically refers to ''abnormal'' convex curvature of the spine. The normal outward (convex) curvature in the thoracic and sacral regions is also termed ''kyphosis'' or ''kyphotic''. The term comes from the Greek lordōsis, from ''lordos'' ("bent backward"). Lordosis in the human spine makes it easier for humans to bring the bulk of their mass over the pelvis. This allows for a much more efficient walking gait than that of other primates, whose inflexible spines cause them to resort to an inefficient forward leaning "bent-knee, bent-waist" gait. As such, lordosis in the human spine is considered one of the primary physiological adaptations of the human skeleton that allows for human gait to be as energetically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrocephaly
Macrocephaly is a condition in which circumference of the human head is abnormally large. It may be pathological or harmless, and can be a familial genetic characteristic. People diagnosed with macrocephaly will receive further medical tests to determine whether the syndrome is accompanied by particular disorders. Those with benign or familial macrocephaly are considered to have megalencephaly. Causes Many people with abnormally large heads or large skulls are healthy, but macrocephaly may be pathological. Pathologic macrocephaly may be due to megalencephaly (enlarged brain), hydrocephalus (abnormally increased cerebrospinal fluid), cranial hyperostosis (bone overgrowth), and other conditions. Pathologic macrocephaly is called "syndromic", when it is associated with any other noteworthy condition, and "nonsyndromic" otherwise. Pathologic macrocephaly may be caused by congenital anatomic abnormalities, genetic conditions, or by environmental events. Many genetic conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development (a ''de novo'' mutation), or it can be inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA (due to their size). There are well over 6,000 known genet ... [...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] |
Jason Acuña
Jason Shannon Acuña (born May 16, 1973), better known by his stage name Wee Man, is an American stunt performer, television personality, professional skateboarder, and actor. He is one of the stars of '' Jackass'' and the host of Fox Sports Net's skateboarding show ''54321''. Acuña has achondroplasia, a form of dwarfism. Life and career Born in Pisa, Italy, Acuña grew up in Torrance, California, and attended North High School. He is of Mexican and German descent. He was the subscription manager for the skateboard magazine '' Big Brother''. His association with that magazine led him to become involved with the '' Jackass'' television series in 2000. Acuña's ''Jackass'' antics include skating as an Oompa-Loompa, kicking himself in the head, dressing as a king while rolling Johnny Knoxville down a staircase in a red carpet, and doing deep-knee bends while holding basketball star Shaquille O'Neal on his back. A recurring gag involves Preston Lacy asking someone to help him ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
