The Broad Autism Phenotype: Just a Little Bit of Autism
Apr 28, · Phenotype Definition. A phenotype is the physical expression of DNA. In contrast, the genotype is the chemical makeup of DNA that causes a particular phenotype. DNA is first transposed into RNA, a slightly different information molecule, which can then be translated into a protein. Phenotypes are caused by the interactions of the many different proteins created by DNA. The Broad Autism Phenotype Questionnaire: Prevalence and Diagnostic Classification. Autism Res, 6: – doi/aur Losh M, Childress D, Lam K, Piven J. Defining Key Features of the Broad Autism Phenotype: A Comparison Across Parents of Multiple- .
This blood phenotype was first discovered in Bombay by Dr. Bhende in The first person found to have the Js phenotype had a blood type that reacted to other blood types in a way never seen before. The serum contained antibodies that attacked all red blood cells of normal ABO phenotypes. The red blood cells appeared to lack all of the ABO blood how to write a hypothosis antigens and to have an additional antigen that was previously unknown.
Individuals with the rare Bombay phenotype hh do not express H antigen also called substance Hthe antigen which is present in blood group O. As a result, they cannot make A antigen also phenotyps substance A or B antigen substance B tye their red blood cells, whatever alleles they may have of the A and B blood-group genes, because A antigen and B antigen are made from H antigen.
For this reason people who have Bombay phenotype can donate red blood cells to any member of the ABO blood group system unless some other blood factor gene, such as Rhis incompatiblebut they cannot receive blood from any member of the ABO blood group system which always contains one or more of A, B or H antigensbut only from other people who have Bombay phenotype.
Receiving blood which contains an antigen which has never been in the patient's own blood causes an immune reaction due to the immune system of a hypothetical receiver producing immunoglobulins not only against antigen A and B, but also against H antigen. The most common immunoglobulins synthesized are IgM and IgG. This seems to have a very important role in the low frequency of hemolytic disease of the newborn among non-Bombay offspring of Bombay mothers.
It is very important, in order to avoid any complications during a blood transfusion, to detect Bombay phenotype individuals, because the usual tests for ABO blood group system would show them as group O. Since anti-H immunoglobulins can activate the complement cascade, it will lead to the lysis of red blood cells while they are still in the circulation, provoking an acute hemolytic transfusion reaction.
This, of course, cannot be prevented unless the lab technologist that is involved is aware of the existence of the Bombay blood group and has the means to test for it.
This very rare phenotype is generally present in about 0. Given that this condition is very rare, any person with this blood group who needs an urgent blood transfusion will probably be unable to get it, as no blood bank would have any in stock. Those anticipating the need for blood transfusion may bank blood for their own use, but of course this option is not available in cases of accidental injury. For example, by only one Colombian person was known to have this phenotype, and blood had to be imported from Brazil for a transfusion.
Biosynthesis of the H, A and B antigens involves a series of enzymes glycosyl transferases that transfer monosaccharides. The resulting antigens are oligosaccharide chains, which are attached to lipids and proteins that are anchored in the red blood cell membrane.
The function ghe the H antigen, apart from being an intermediate substrate in the synthesis of ABO blood group antigens, is not known, although it may be involved in cell adhesion. People who lack the H antigen do not suffer from deleterious effects, and being H-deficient is only an issue if they need a blood transfusion, because they would need blood without the H antigen present on red blood cells. The specificity of the H antigen is determined by the sequence of oligosaccharides.
More specifically, the minimum requirement for H antigenicity is the terminal disaccharide fucose - galactosewhere the fucose has an alpha wbat. This antigen is produced by a specific fucosyl transferase Galactoside 2-alpha-L-fucosyltransferase 2 that catalyzes the final step in the synthesis of the molecule. If a person has group O blood, the H antigen remains unmodified. Therefore, the H antigen is present more in blood type O and less in blood type AB.
Two regions of the genome encode two enzymes with very similar substrate specificities: the H locus FUT1 which encodes the Fucosyl transferase and the Se locus FUT2 that instead indirectly encodes a soluble form of the H antigen, which is found in bodily secretions. Both genes are on chromosome 19 at q.
Because they are highly homologous, they are likely to have how long does it take for focalin to work the result of a gene duplication of a common gene ancestor. The H locus contains four exons that span more than 8 kb of genomic DNA. The mutation whah a stop codon, leading to a truncated enzyme that lacks 50 amino acids at the C-terminal end, rendering the enzyme inactive.
In Caucasians, the Bombay phenotype may be caused ;henotype a number of mutations. Likewise, a number of mutations have been reported to underlie the para-Bombay phenotype. The Se locus contains the FUT2 gene, which is expressed in secretory glands. They produce a soluble form of H antigen that is found in saliva and other bodily fluids.
The enzyme encoded by FUT2 is also involved in the thhe of antigens of the Lewis blood group. Bombay phenotype occurs in individuals who have inherited two recessive alleles of the H gene how much to add a story to a house. These individuals do not produce the H carbohydrate that is the precursor to the A and B thee, meaning that individuals may possess alleles for either or both of the A and B alleles without being able to express them.
Because both parents must carry this recessive allele to transmit this blood type to their children, the condition mainly occurs in small closed-off communities where there is a good chance of both og of a child either being of Bombay type, or being heterozygous for the h allele and so carrying the Bombay characteristic as recessive. Other examples may include noble families, which are inbred due to custom rather than local genetic variety. In theory, the maternal production of anti-H during pregnancy might cause hemolytic disease in a phfnotype who did not inherit the mother's Bombay phenotype.
In practice, cases of HDN caused in this way have not been described. This may be possible due to the rarity of the Bombay phenotype but also because of the IgM produced by the immune system of the mother.
Since IgMs are not transported across the microscopic placental blood vessels like IgG are they cannot reach the blood stream of the fetus to provoke the expected acute hemolytic reaction.
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Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Blood Groups and Red Cell Antigens. Retrieved El Colombiano in Spanish. Blood transfusion and transfusion medicine. Transfusion hemosiderosis Transfusion related acute lung injury Transfusion associated circulatory overload Transfusion-associated graft versus host disease What is a contact lenses non-hemolytic transfusion what does ephedrine do to the body Hemolytic reaction acute delayed Serum sickness Transfusion transmitted infection.
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What's the difference between these two genetics terms?
Jun 06, · The predominant current-day meaning of genotype is some relevant part of the DNA passed to the organism by its parents. The phenotype is the physical and behavioral traits of the organism, for example, size and shape, metabolic activities, and patterns of movement. The distinction between them is especially important in evolutionary theory, where the survival and mating of . This information is determined by the genes passed on by the parents at conception. An individual’s phenotype only includes expressed genes. For example, if an individual has one “brown hair” allele and one “blonde hair” allele, and they have brown hair, their phenotype . Jan 18, · The phenotype is the actual physical features shown by the organism. In pea plants, like in the example above, if the dominant allele for purple flowers is present in the genotype, then the phenotype would be purple. Even if the genotype had one purple color allele and one recessive white color allele, the phenotype would still be a purple flower.
Let's ask a somewhat more complex question. If this couple has a total of four children, what is the probability that 3 of the 4 will show the dominant phenotype? To answer this, we will first derive the appropriate formula and then use it to calculate the numerical answer. The same formula allows us to understand the expected statistical distribution of the various possible phenotype patterns in four-child or any other size families in a large population.
Review: How can some simple overall probabilities be calculated by combining the multiplication and addition "rules" we covered earlier? Let's start with a very simple case: asking about gender probabilities in families of three children. What is the probability that all three children in a family will be the same gender? How can we understand and use "Pascal's triangle" and the "general rule for repeated trials of events with constant probabilities", formula 1 page in textbook?
Consider the numerators of the fractions in the above three-child family gender equation: 1 , 3 , 3 , 1. Figure 4. The numbers in any row can be used just as described above. For example, assume that over the next two decades you have 6 kids.
There are 64 possible gender birth orders, with 20 of these resulting in you having three girls and three boys. The terms p and q are the individual probabilities for a specific outcome from a single "event".
For "dominant : recessive phenotype" type of calculations, p and q will usually not be equal. Generalizing this, we get to the formula on page in your text that is "the general rule for repeated trials of events with constant probabilities". The term n! This number can either be calculated or taken directly from Pascal's triangle.
Sample problem: You and your mate are both heterozygous for some simple Mendelian gene alpha i. Over the next decade, you proceed to have four children. What is the probability that 3 of your children will show the dominant phenotype and one will show the recessive phenotype? What are the probabilities of the other possible outcomes? If we were looking at thousands of such families, we know that the overall ratio of dominant to recessive phenotypes in the children would average out to , as shown by a simple Punnett square.
But for one couple having four children, what's the probability, P 3D,1r? Problem S "Heterozygous parents; have three children". Do the calculations for the probabilities that all three, two, one, or none of the three children will show the dominant phenotype from gene alpha. Construct the graph and compare the result with the "four children" graph done in class.