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18 Trisomy Syndrome
Edwards syndrome, also known as trisomy 18, is a genetic disorder caused by the presence of a third copy of all or part of chromosome 18. Many parts of the body are affected. Babies are often born small and have heart defects. Other features include a small head, small jaw, clenched fists with overlapping fingers, and severe intellectual disability. Most cases of Edwards syndrome occur due to problems during the formation of the reproductive cells or during early development. The rate of disease increases with the mother's age. Rarely, cases may be inherited from a person's parents. Occasionally, not all cells have the extra chromosome, known as mosaic trisomy, and symptoms in these cases may be less severe. An ultrasound during pregnancy can increase suspicion for the condition, which can be confirmed by amniocentesis. Treatment is supportive. After having one child with the condition, the risk of having a second is typically around one percent. It is the second-most com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyotype
A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Development
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervous syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esophageal Atresia
Esophageal can refer to: * The esophagus * Esophageal arteries * Esophageal glands The esophageal glands are glands that are part of the digestive system of various animals, including humans. In humans Esophageal glands in humans are a part of a human digestive system. They are a small compound racemose exocrine glands of the m ... * Esophageal cancer {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omphalocele
Omphalocele or omphalocoele also called exomphalos, is a rare abdominal wall defect. Beginning at the 6th week of development, rapid elongation of the gut and increased liver size reduces intra abdominal space, which pushes intestinal loops out of the abdominal cavity. Around 10th week, the intestine returns to the abdominal cavity and the process is completed by the 12th week. Persistence of intestine or the presence of other abdominal viscera (e.g. stomach, liver) in the umbilical cord results in an omphalocele. Omphalocele occurs in 1 in 4,000 births and is associated with a high rate of mortality (25%) and severe malformations, such as cardiac anomalies (50%), neural tube defect (40%), exstrophy of the bladder and Beckwith–Wiedemann syndrome. Approximately 15% of live-born infants with omphalocele have chromosomal abnormalities. About 30% of infants with an omphalocele have other congenital abnormalities. Signs and symptoms The sac, which is formed from an outpouching of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patent Ductus Arteriosus
''Patent ductus arteriosus'' (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta, which has a higher pressure, to the pulmonary artery. Symptoms are uncommon at birth and shortly thereafter, but later in the first year of life there is often the onset of an increased work of breathing and failure to gain weight at a normal rate. With time, an uncorrected PDA usually leads to pulmonary hypertension followed by right-sided heart failure. The ''ductus arteriosus'' is a fetal blood vessel that normally closes soon after birth. In a PDA, the vessel does not close, but remains ''patent'' (open), resulting in an abnormal transmission of blood from the aorta to the pulmonary artery. PDA is common in newborns with persistent respiratory problems such as hypoxia, and has a high occurrence in premature newborns. Premature newborns are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrial Septal Defect
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO). It is common in patients with a congenital atrial septal aneurysm (ASA). After PFO closure the atria normally are separated by a dividing wall, the interatrial septum. If this septum is defective or absent, then oxygen-rich blood can flow directly from the left side of the heart to mix with the oxygen-poor blood in the right side of the heart; or the opposite, depending on whether the left or right atrium has the higher blood pressure. In the absence of other heart defects, the left atrium has the higher pressure. This can lead to lower-than-normal oxygen levels in the arterial blood that supplies the brain, organs, and tissues. However, an ASD m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventricular Septal Defect
A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one common ventricle. The ventricular septum consists of an inferior muscular and superior membranous portion and is extensively innervated with conducting cardiomyocytes. The membranous portion, which is close to the atrioventricular node, is most commonly affected in adults and older children in the United States. It is also the type that will most commonly require surgical intervention, comprising over 80% of cases. Membranous ventricular septal defects are more common than muscular ventricular septal defects, and are the most common congenital cardiac anomaly. Signs and symptoms Ventricular septal defect is usually symptomless at birth. It usually manifests a few weeks after birth. VSD is an acyanotic congenital heart defect, aka a lef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overlapping Fingers
Overlap may refer to: * In set theory, an overlap of elements shared between sets is called an intersection, as in a Venn diagram. * In music theory, overlap is a synonym for reinterpretation of a chord at the boundary of two musical phrases * Overlap (railway signalling), the length of track beyond a stop signal that is proved to be clear of obstructions as a safety margin * Overlap (road), a place where multiple road numbers overlap * Overlap (term rewriting), in mathematics, computer science, and logic, a property of the reduction rules in term rewriting systems * Overlap add, an efficient convolution method using FFT * Overlap coefficient, a similarity measure between sets * Orbital overlap In chemical bonds, an orbital overlap is the concentration of orbitals on adjacent atoms in the same regions of space. Orbital overlap can lead to bond formation. Linus Pauling explained the importance of orbital overlap in the molecular bond ang ..., important concept in quantum mechani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Hilton Edwards
John Hilton Edwards (26 March 1928 – 11 October 2007) was a British medical geneticist. Edwards reported the first description of a syndrome of multiple congenital malformations associated the presence of an extra chromosome. The extra chromosome belonged to the E group of chromosomes which consisted of chromosomes 16, 17 and 18. The condition is now known as Edwards syndrome or trisomy 18 syndrome. In 1979, Edwards was elected to fellowship of the Royal Society. He was a Fellow of Keble College, Oxford, and Professor of Genetics at Oxford from 1979 to 1995. He was the son of the surgeon Harold C. Edwards. His brother is the geneticist and statistician A.W.F. Edwards. Early in his career, he worked under Lancelot Hogben Lancelot Thomas Hogben FRS FRSE (9 December 1895 – 22 August 1975) was a British experimental zoologist and medical statistician. He developed the African clawed frog ''(Xenopus laevis)'' as a model organism for biological research in his ear ..., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Down Syndrome
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual disability, and characteristic facial features. The average IQ of a young adult with Down syndrome is 50, equivalent to the mental ability of an eight- or nine-year-old child, but this can vary widely. The parents of the affected individual are usually genetically normal. The probability increases from less than 0.1% in 20-year-old mothers to 3% in those of age 45. The extra chromosome is believed to occur by chance, with no known behavioral activity or environmental factor that changes the probability. Down syndrome can be identified during pregnancy by prenatal screening followed by diagnostic testing or after birth by direct observation and genetic testing. Since the introduction of screening, Down syndrome pregnancies are often abor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Trisomy
A trisomy is a type of polysomy in which there are three instances of a particular chromosome, instead of the normal two. A trisomy is a type of aneuploidy (an abnormal number of chromosomes). Description and causes Most organisms that reproduce sexually have pairs of chromosomes in each cell, with one chromosome inherited from each parent. In such organisms, a process called meiosis creates cells called gametes (eggs or sperm) that have only one set of chromosomes. The number of chromosomes is different for different species. Humans have 46 chromosomes (i.e. 23 pairs of chromosomes). Human gametes have only 23 chromosomes. If the chromosome pairs fail to separate properly during cell division, the egg or sperm may end up with a second copy of one of the chromosomes. (''See'' non-disjunction.) If such a gamete results in fertilization and an embryo, the resulting embryo may also have an entire copy of the extra chromosome. Terminology The number of chromosomes in the cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therapy
A therapy or medical treatment (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a medical diagnosis. As a rule, each therapy has indications and contraindications. There are many different types of therapy. Not all therapies are effective. Many therapies can produce unwanted adverse effects. ''Medical treatment'' and ''therapy'' are generally considered synonyms. However, in the context of mental health, the term ''therapy'' may refer specifically to psychotherapy. History Before the creating of therapy as a formal procedure, people told stories to one another to inform and assist about the world. The term "healing through words" was used over 3,500 years ago in Greek and Egyptian writing. The term psychotherapy was invented in the 19th century, and psychoanalysis was founded by Sigmund Freud under a decade later. Semantic field The words ''care'', ''therapy'', ''treatment'', and ''intervention'' overlap in a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
