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Sclerosteosis
Sclerosteosis is an autosomal recessive disorder characterized by bone overgrowth. It was first described in 1958 but given the current name in 1967. Excessive bone formation is most prominent in the skull, mandible and tubular bones. It can cause facial distortion and syndactyly. Increased intracranial pressure can cause sudden death in patients. It is a rare disorder that is most prominent in the Afrikaner population in South Africa (40 patients), but there have also been cases of American and Brazilian families. Cause Sclerosteosis is caused by mutations in the gene that encode for the sclerostin Sclerostin is a protein that in humans is encoded by the ''SOST'' gene. Sclerostin is a secreted glycoprotein with a C-terminal cysteine knot-like (CTCK) domain and sequence similarity to the DAN (differential screening-selected gene aberrative ... protein. The sclerostin protein is necessary in inhibiting canonical wnt signalling. Wnt signalling results in increased osteoblast acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes ( autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance such as incomplete d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium ( facial skeleton) that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton. Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds. In some animals, such as horned ungulates (mammals with hooves), the skull also has a defensive function by providing the mount (on the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints. The bone is formed prenatal development, in the fetus from a fusion of the left and right mandibular prominences, and the point where these sides join, the mandibular symphysis, is still visible as a faint ridge in the midline. Like other symphyses in the body, this is a midline articulation where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 59 The word "mandible" derives from the Latin word ''mandibula'', "jawbone" (literally "one used for chewing"), from ''wikt:mandere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syndactyly
Syndactyly is a condition wherein two or more digits are fused together. It occurs normally in some mammals, such as the siamang and diprotodontia, but is an unusual condition in humans. The term is from Greek σύν, ''syn'' 'together' and δάκτυλος, ''daktulos'' 'finger'. Classification Syndactyly can be simple or complex. * In simple syndactyly, adjacent fingers or toes are joined by soft tissue. * In complex syndactyly, the bones of adjacent digits are fused. The kangaroo exhibits complex syndactyly. Syndactyly can be complete or incomplete. * In complete syndactyly, the skin is joined all the way to the tip of the involved digits. * In incomplete syndactyly, the skin is only joined part of the distance to the tip of the involved digits. Complex syndactyly occurs as part of a syndrome (such as Apert syndrome) and typically involves more digits than simple syndactyly. Fenestrated syndactyly, also known as acrosyndactyly or terminal syndactyly, means the skin is joine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afrikaner
Afrikaners () are a South African ethnic group descended from Free Burghers, predominantly Dutch settlers first arriving at the Cape of Good Hope in the 17th and 18th centuries.Entry: Cape Colony. ''Encyclopædia Britannica Volume 4 Part 2: Brain to Casting''. Encyclopædia Britannica, Inc. 1933. James Louis Garvin, editor. They traditionally dominated South Africa's politics and commercial agricultural sector prior to 1994. Afrikaans, South Africa's third most widely spoken home language, evolved as the First language, mother tongue of Afrikaners and most Cape Coloureds. It originated from the Dutch language, Dutch vernacular of South Holland, incorporating words brought from the Dutch East Indies (now Indonesia) and Madagascar by slaves. Afrikaners make up approximately 5.2% of the total South African population, based upon the number of White South Africans who speak Afrikaans as a first language in the South African National Census of 2011. The arrival of Portugal, Portug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini. It also completely enclaves the country Lesotho. It is the southernmost country on the mainland of the Old World, and the second-most populous country located entirely south of the equator, after Tanzania. South Africa is a biodiversity hotspot, with unique biomes, plant and animal life. With over 60 million people, the country is the world's 24th-most populous nation and covers an area of . South Africa has three capital cities, with the executive, judicial and legislative branches of government based in Pretoria, Bloemfontein, and Cape Town respectively. The largest city is Johannesburg. About 80% of the population are Black South Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sclerostin
Sclerostin is a protein that in humans is encoded by the ''SOST'' gene. Sclerostin is a secreted glycoprotein with a C-terminal cysteine knot-like (CTCK) domain and sequence similarity to the DAN (differential screening-selected gene aberrative in neuroblastoma) family of bone morphogenetic protein (BMP) antagonists. Sclerostin is produced primarily by the osteocyte but is also expressed in other tissues, and has anti-anabolic effects on bone formation. Structure The sclerostin protein, with a length of 213 residues, has a secondary structure that has been determined by protein NMR to be 28% beta sheet (6 strands; 32 residues). Function Sclerostin, the product of the SOST gene, located on chromosome 17q12–q21 in humans, was originally believed to be a non-classical bone morphogenetic protein (BMP) antagonist. More recently, sclerostin has been identified as binding to LRP5/ 6 receptors and inhibiting the Wnt signaling pathway. The inhibition of the Wnt pathway leads to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
