Atresia
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Atresia
Atresia is a condition in which an orifice or passage in the body is (usually abnormally) closed or absent. Examples of atresia include: *Aural atresia, a congenital deformity where the ear canal is underdeveloped. * Biliary atresia, a condition in newborns in which the common bile duct between the liver and the small intestine is blocked or absent. * Congenital bronchial atresia, a rare congenital abnormality * Choanal atresia, blockage of the back of the nasal passage, usually by abnormal bony or soft tissue. * Esophageal atresia, which affects the alimentary tract and causes the esophagus to end before connecting normally to the stomach. *Follicular atresia, degeneration and resorption of the ovarian follicles.   * Imperforate anus, malformation of the opening between the rectum and anus. * Intestinal atresia, malformation of the intestine, usually resulting from a vascular accident in utero. * Microtia, absence of the ear canal or failure of the canal to be tubular or fully fo ...
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Biliary Atresia
Biliary atresia, also known as extrahepatic ductopenia and progressive obliterative cholangiopathy, is a childhood disease of the liver in which one or more bile ducts are abnormally narrow, blocked, or absent. It can be congenital or acquired. It has an incidence of one in 10,000–15,000 live births in the United States, and a prevalence of one in 16,700 in the British Isles. Biliary atresia is most common in East Asia, with a frequency of one in 5,000. The cause of biliary atresia in Egyptian infants has been proven to be as a result of aflatoxin induced cholangiopathy acquired prenatally in infants who have glutathione S transferase M1 deficiency. The biliary atresia phenotype caused by congenital aflatoxicosis in GST M1 deficient neonates is named Kotb disease. Syndromic biliary atresia (e.g. Biliary Atresia Splenic Malformation (BASM)) has been associated with certain genes (e.g. Polycystic Kidney Disease 1 Like 1 - PKD1L1), and some infants with isolated biliary atresia ...
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Microtia
Microtia is a congenital deformity where the auricle (external ear) is underdeveloped. A completely undeveloped pinna is referred to as anotia. Because microtia and anotia have the same origin, it can be referred to as microtia-anotia. Microtia can be unilateral (one side only) or bilateral (affecting both sides). Microtia occurs in 1 out of about 8,000–10,000 births. In unilateral microtia, the right ear is most commonly affected. It may occur as a complication of taking Accutane (isotretinoin) during pregnancy. Classification According to the Altman-classification, there are four grades of microtia: *Grade I: A less than complete development of the external ear with identifiable structures and a small but present external ear canal *Grade II: A partially developed ear (usually the top portion is underdeveloped) with a closed stenotic external ear canal producing a conductive hearing loss. *Grade III: Absence of the external ear with a small peanut-like vestige structure a ...
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Intestinal Atresia
Intestinal atresia is any congenital malformation of the structure of the intestine that causes bowel obstruction. The malformation can be a narrowing (stenosis), absence or malrotation of a portion of the intestine. These defects can either occur in the small or large intestine. Symptoms and signs The most prominent symptom of intestinal atresia is bilious vomiting soon after birth. This is most common in jejunal atresia. Other features include abdominal distension and failure to pass meconium. The distension is more generalised the further down the bowel the atresia is located and is thus most prominent with ileal atresia. Inability to pass stool is most common with duodenal or jejunal atresia; if stool is passed, it may be small, mucus-like and grey. Occasionally, there may be jaundice, which is most common in jejunal atresia. Abdominal tenderness or an abdominal mass are not generally seen as symptoms of intestinal atresia. Rather, abdominal tenderness is a symptom of the l ...
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Aural Atresia
Microtia is a congenital deformity where the auricle (external ear) is underdeveloped. A completely undeveloped pinna is referred to as anotia. Because microtia and anotia have the same origin, it can be referred to as microtia-anotia. Microtia can be unilateral (one side only) or bilateral (affecting both sides). Microtia occurs in 1 out of about 8,000–10,000 births. In unilateral microtia, the right ear is most commonly affected. It may occur as a complication of taking Accutane (isotretinoin) during pregnancy. Classification According to the Altman-classification, there are four grades of microtia: *Grade I: A less than complete development of the external ear with identifiable structures and a small but present external ear canal *Grade II: A partially developed ear (usually the top portion is underdeveloped) with a closed stenotic external ear canal producing a conductive hearing loss. *Grade III: Absence of the external ear with a small peanut-like vestige structure a ...
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Follicular Atresia
Follicular atresia refers to the process in which a follicle fails to develop, thus preventing it from ovulating and releasing an egg. It is a normal, naturally occurring progression that occurs as mammalian ovaries age. Approximately 1% of mammalian follicles in ovaries undergo ovulation and the remaining 99% of follicles go through follicular atresia as they cycle through the growth phases. In summary, follicular atresia is a process that leads to the follicular loss and loss of oocytes, and any disturbance or loss of functionality of this process can lead to many other conditions. Background Ovaries are the site of development and breakdown of ovarian follicles which secrete hormones and oocytes. Oocytes are immature eggs and are surrounded by granulosa cells and internal and external theca cells. Oocytes are then able to mature within the follicle through meiosis. In humans with ovaries, this process occurs continuously, as they are born with a finite number of follicles (b ...
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Ovarian Follicle Atresia
Follicular atresia refers to the process in which a follicle fails to develop, thus preventing it from ovulating and releasing an egg. It is a normal, naturally occurring progression that occurs as mammalian ovaries age. Approximately 1% of mammalian follicles in ovaries undergo ovulation and the remaining 99% of follicles go through follicular atresia as they cycle through the growth phases. In summary, follicular atresia is a process that leads to the follicular loss and loss of oocytes, and any disturbance or loss of functionality of this process can lead to many other conditions. Background Ovaries are the site of development and breakdown of ovarian follicles which secrete hormones and oocytes. Oocytes are immature eggs and are surrounded by granulosa cells and internal and external theca cells. Oocytes are then able to mature within the follicle through meiosis. In humans with ovaries, this process occurs continuously, as they are born with a finite number of follicles (b ...
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Pulmonary Atresia
Pulmonary atresia is a congenital malformation of the pulmonary valve in which the valve orifice fails to develop. The valve is completely closed thereby obstructing the outflow of blood from the heart to the lungs. The pulmonary valve is located on the right side of the heart between the right ventricle and pulmonary artery. In a normal functioning heart, the opening to the pulmonary valve has three flaps that open and close In congenital heart defects such as pulmonary atresia, structural abnormalities can include the valves of the heart, and the walls and arteries/veins near the heart muscle. Consequently, blood flow due to the aforementioned structural abnormalities is affected, either by blocking or altering the flow of blood through the human cardiac muscle. Signs and symptoms The symptoms/signs of pulmonary atresia that will occur in babies are consistent with cyanosis, some fatigue and some shortness of breath (eating may be a problem as well). In the case of pulmonary atr ...
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Choanal Atresia
Choanal atresia is a congenital disorder where the back of the nasal passage (choana) is blocked, usually by abnormal bony or soft tissue (membranous) due to failed hole development of the nasal fossae during prenatal development. It causes persistent rhinorrhea, and with bilateral choanal atresia and obstructed airway that can cause cyanosis and hypoxia. Choanal atresia is diagnosed based on the inability to place a nasal catheter, and radiology results (particularly CT scans). Treatment involves maintaining an open airway, and may involve surgery to reopen the airway, potentially with a stent. Choanal atresia is a fairly rare condition, affecting between 1 in 7,000 to 1 in 5,000 live births. Presentation Choanal atresia can be unilateral or bilateral. * A unilateral choanal atresia may not be detected until much later in life because the baby manages to get along with only one nostril available for breathing. Symptoms are minor, including persistent rhinorrhea (mainly nor ...
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Vaginal Atresia
Vaginal atresia is a condition in which the vagina is abnormally closed or absent. The main causes can either be complete vaginal hypoplasia, or a vaginal obstruction, often caused by an imperforate hymen or, less commonly, a transverse vaginal septum. It results in uterovaginal outflow tract obstruction. This condition does not usually occur by itself within an individual, but coupled with other developmental disorders within the female. The disorders that are usually coupled with a female who has vaginal atresia are Mayer-Rokitansky-Küster-Hauser syndrome, Bardet-Biedl syndrome, or Fraser syndrome. One out of every 5,000 women have this abnormality. Symptoms and signs Symptoms and signs in the newborn can be sepsis, abdominal mass, and respiratory distress. Other abdominopelvic or perineal congenital anomalies frequently prompt radiographic evaluation in the newborn, resulting in a diagnosis of coincident vaginal atresia. Symptoms for vaginal atresia include cyclical abdominal ...
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Tricuspid Atresia
Tricuspid atresia is a form of congenital heart disease whereby there is a complete absence of the tricuspid valve. Therefore, there is an absence of right atrioventricular connection. This leads to a hypoplastic (undersized) or absent right ventricle. This defect is contracted during prenatal development, when the heart does not finish developing. It causes the systemic circulation to be filled with relatively deoxygenated blood. The causes of tricuspid atresia are unknown. In most cases of tricuspid atresia, additional defects exist to allow exchange of blood between the loops of systematic circulation and pulmonary circulation, filling in the role of the missing atrioventricular connection. An atrial septal defect (ASD) must be present to fill the left atrium and the left ventricle with blood. Since there is a lack of a right ventricle, there must also be a way to pump blood into the pulmonary artery. This can be accomplished by a ventricular septal defect (VSD) connecting the l ...
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Congenital Bronchial Atresia
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth defects are divided into two main types: structural disorders in which problems are seen with the shape of a body part and functional disorders in which problems exist with how a body part works. Functional disorders include metabolic and degenerative disorders. Some birth defects include both structural and functional disorders. Birth defects may result from genetic or chromosomal disorders, exposure to certain medications or chemicals, or certain infections during pregnancy. Risk factors include folate deficiency, drinking alcohol or smoking during pregnancy, poorly controlled diabetes, and a mother over the age of 35 years old. Many are believed to involve multiple factors. Birth defects may be visib ...
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Imperforate Anus
An imperforate anus or anorectal malformations (ARMs) are birth defects in which the rectum is malformed. ARMs are a spectrum of different congenital anomalies which vary from fairly minor lesions to complex anomalies. The cause of ARMs is unknown; the genetic basis of these anomalies is very complex because of their anatomical variability. In 8% of patients, genetic factors are clearly associated with ARMs. Anorectal malformation in Currarino syndrome represents the only association for which the gene ''HLXB9'' has been identified. Types There are other forms of anorectal malformations though imperforate anus is most common. Other variants include anterior ectopic anus. This form is more commonly seen in females and presents with constipation. Presentation There are several forms of imperforate anus and anorectal malformations. The new classification is in relation of the type of associated fistula. The classical Wingspread classification was in low and high anomalies: * A lo ...
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