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Anal Atresia
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 cloacal malformation, rectal atresia, rectal stenosis, and 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 Wingspread c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birth Defects
A birth defect 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 birth defects are believed to involve multiple factors. Birth defects may be visible at birth or di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptile
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocephalia. About 12,000 living species of reptiles are listed in the Reptile Database. The study of the traditional reptile orders, customarily in combination with the study of modern amphibians, is called herpetology. Reptiles have been subject to several conflicting Taxonomy, taxonomic definitions. In Linnaean taxonomy, reptiles are gathered together under the Class (biology), class Reptilia ( ), which corresponds to common usage. Modern Cladistics, cladistic taxonomy regards that group as Paraphyly, paraphyletic, since Genetics, genetic and Paleontology, paleontological evidence has determined that birds (class Aves), as members of Dinosauria, are more closely related to living crocodilians than to other reptiles, and are thus nested among re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baller–Gerold Syndrome
Baller–Gerold syndrome (BGS) is a rare genetic syndrome that involves premature fusion of the skull bones and malformations of facial, forearm and hand bones. The symptoms of Baller–Gerold syndrome overlap with features of a few other genetics disorders: Rothmund–Thomson syndrome and Rapadilino syndrome, RAPADILINO syndrome. The prevalence of BGS is unknown, as there have only been a few reported cases, but it is estimated to be less than 1 in a million. The name of the syndrome comes from the researchers Baller and Gerold who discovered the first three cases. Signs and symptoms The most common and defining features of BGS are craniosynostosis and radial ray deficiency. The observations of these features allow for a diagnosis of BGS to be made, as these symptoms characterize the syndrome. Craniosynostosis involves the pre-mature fusion of bones in the skull. The coronal craniosynostosis that is commonly seen in patients with BGS results in the fusion of the skull along the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 22
Chromosome 22 is one of the 23 pairs of chromosomes in human cells. Humans normally have two copies of chromosome 22 in each cell. Chromosome 22 is the second smallest human chromosome, spanning about 51 million DNA base pairs and representing between 1.5 and 2% of the total DNA in cells. In 1999, researchers working on the Human Genome Project announced they had determined the sequence of base pairs that make up this chromosome. Chromosome 22 was the first human chromosome to be fully sequenced. Human chromosomes are numbered by their apparent size in the karyotype, with chromosome 1 being the largest and chromosome 22 having originally been identified as the smallest. However, genome sequencing has revealed that chromosome 21 is actually smaller than chromosome 22. Genes Number of genes The following are some of the gene count estimates of human chromosome 22. Because researchers use different approaches to genome annotation, their predictions of the number of genes on e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrasomy
A tetrasomy is a form of aneuploidy with the presence of four copies, instead of the normal two, of a particular chromosome. Causes Full Full tetrasomy of an individual occurs due to non-disjunction when the cells are dividing (meiosis I or II) to form egg and sperm cells ( gametogenesis). This can result in extra chromosomes in a sperm or egg cell. After fertilization, the resulting fetus has 48 chromosomes instead of the typical 46. Autosomal tetrasomies * Cat eye syndrome where partial tetrasomy of chromosome 22 is present * Pallister-Killian syndrome (tetrasomy 12p) * Tetrasomy 9p * Tetrasomy 18p * Tetrasomy 21 A tetrasomy is a form of aneuploidy with the presence of four copies, instead of the normal two, of a particular chromosome. Causes Full Full tetrasomy of an individual occurs due to non-disjunction when the cell division, cells are dividing (mei ..., a rare form of Down syndrome Sex-chromosome tetrasomies * Tetrasomy X * XXYY syndrome * XXXY syndrome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 of each type of chromosome inherited from each parent. In such organisms, meiosis creates gamete cells (eggs or sperm) having only one set of chromosomes. The number of chromosomes is different for different species, with humans having 46 chromosomes (23 pairs) and human gametes 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 ( non-disjunction). If such a gamete is fertilized with a normal gamete, the resulting embryo may have a total of three copies of the chromosome. Terminology The number of chromosomes in the cell where trisomy occurs is represented as, for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cat-eye Syndrome
Cat-eye syndrome (CES) or Schmid–Fraccaro syndrome is a rare condition caused by an abnormal extra chromosome, i.e. a small supernumerary marker chromosome. This chromosome consists of the entire short arm and a small section of the long arm of chromosome 22. In consequence, individuals with the cat-eye syndrome have three ( trisomic) or four ( tetrasomic) copies of the genetic material contained in the abnormal chromosome instead of the normal two copies. The prognosis for patients with CES varies depending on the severity of the condition and their associated signs and symptoms, especially when heart or kidney abnormalities are seen. Signs and symptoms * Unilateral or bilateral iris coloboma (absence of tissue from the colored part of the eyes) * Preauricular pits/tags (small depressions/growths of skin on the outer ears) * Anal atresia (abnormal obstruction of the anus) * Downward-slanting palpebral fissures (openings between the upper and lower eyelids) * Cleft palate * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VACTERL Association
The VACTERL association (also VATER association, and less accurately VACTERL syndrome) refers to a recognized group of birth defects which tend to co-occur (see below). This pattern is a recognized association, as opposed to a syndrome, because there is no known pathogenetic cause to explain the grouped incidence. Each child with this condition can be unique. At present this condition is treated after birth with issues being approached one at a time. Some infants are born with symptoms that cannot be treated and they do not survive. VACTERL association can be linked to other similar conditions such as Klippel Feil and Goldenhar syndrome including crossovers of conditions. No specific genetic or chromosome problem has been identified with VACTERL association. VACTERL can be seen with some chromosomal defects such as Trisomy 18 and is more frequently seen in babies of diabetic mothers. VACTERL association, however, is most likely caused by multiple factors. VACTERL association s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limb (anatomy)
A limb (from Old English ''lim'', meaning "body part") is a jointed, muscled appendage of a tetrapod vertebrate animal used for weight-bearing, terrestrial locomotion and physical interaction with other objects. The distalmost portion of a limb is known as its extremity. The limbs' bony endoskeleton, known as the appendicular skeleton, is homologous among all tetrapods, who use their limbs for walking, running and jumping, swimming, climbing, grasping, touching and striking. All tetrapods have four limbs that are organized into two bilaterally symmetrical pairs, with one pair at each end of the torso, which phylogenetically correspond to the four paired fins ( pectoral and pelvic fins) of their fish ( sarcopterygian) ancestors. The cranial pair (i.e. closer to the head) of limbs are known as the forelimbs or ''front legs'', and the caudal pair (i.e. closer to the tail or coccyx) are the hindlimbs or ''back legs''. In animals with a more erect bipedal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney
In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal artery, renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the urinary bladder, bladder. The kidney participates in the control of the volume of various body fluids, fluid osmolality, Acid-base homeostasis, acid-base balance, various electrolyte concentrations, and removal of toxins. Filtration occurs in the glomerulus (kidney), glomerulus: one-fifth of the blood volume that enters the kidneys is filtered. Examples of substances reabsorbed are solute-free water, sodium, bicarbonate, glucose, and amino acids. Examples of substances secreted are hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esophageal Atresia
Esophageal atresia is a congenital medical condition (birth defect) that affects the alimentary tract. It causes the esophagus to end in a blind-ended pouch rather than connecting normally to the stomach. It comprises a variety of congenital anatomic defects that are caused by an abnormal embryological development of the esophagus. It is characterized anatomically by a congenital obstruction of the esophagus with interruption of the continuity of the esophageal wall. Pathophysiology The genetic causes of EA/TEF include chromosome anomalies or variants in genes involved in critical developmental processes which are dosage sensitive. Several EA/TEF risk genes have been discovered include the transcriptional regulators SOX2, MYCN, CHD7, FANCB, and members of FOX transcription factor family. Others plausible candidate genes in the etiology of EA/TEF were identified as APC2, AMER3, PCDH1, GTF3C1, POLR2B, RAB3GAP2, and ITSN1. Signs and symptoms This birth defect arises in the fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracheoesophageal Fistula
A tracheoesophageal fistula (TEF, or TOF; see spelling differences) is an abnormal connection (fistula) between the esophagus and the trachea. TEF is a common congenital abnormality, but when occurring late in life is usually the sequela of surgical procedures such as a laryngectomy. Presentation Tracheoesophageal fistula is suggested in a newborn by copious salivation associated with choking, coughing, vomiting, and cyanosis coincident with the onset of feeding. Esophageal atresia and the subsequent inability to swallow typically cause polyhydramnios in utero. Rarely it may present in an adult. Complications Surgical repair can sometimes result in complications, including: * Stricture, due to gastric acid erosion of the shortened esophagus * Leak of contents at the point of anastomosis * Recurrence of fistula * Gastro-esophageal reflux disease * Dysphagia * Asthma-like symptoms, such as persistent coughing/wheezing * Recurrent chest infections * Tracheomalacia Associations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
