Chromosome 15 Deletion

For this assignment, I will use the websites, lab and materials from this week and complete an internet search of my own on chromosomes. I will write a two- page essay that explains how conditions caused by extra or missing chromosomes reflect a meiotic error. I will also choose two conditions or diseases to review. Also, distinguish among the modes of inheritance.

For example, wings-clipped P-elements that lack the inverted repeats (not able to be mobilized themselves), which are not internally deleted and can produce a transposase source, can be introduced to the internally-deleted P-element to provide transposase and therefore allow transposition to occur. The provided transposase recognizes and binds to inverted repeats on the internally-deleted P-element, which introduces nicks in the DNA beside the inverted repeats. This allows the element to excise and insert into a new location. If it excises neatly out of the DNA, a deletion will not occur. However, if it excises to a homologue towards the right or the left, due to an error in the excision process, a deletion will occur through this pre-meiotic recombination event.

Anaphase – the chromosomes are divided into single from pair and the chromosomes move to opposite poles

Angelman syndrome is thought to be caused mainly by the deletion of the maternally inherited copy of UEB3A. A small number of cases are also caused by failures in imprinting or, very rarely, monosomy 15 in the egg and disomy 15 in the sperm. The profound mental effects are caused by this gene due to the fact that, while UEB3A’s protein is active in various bodily tissues, only the mother’s copy of the gene is active in the brain.

Researchers have taken the Y-chromosome of higher primates including humans, and great apes (orangutans, chimpanzees, bonobos, gorillas) and ran analysis research. They have discovered that the X and Y chromosomes recombine only at the pseudo autosomal region (PAR), which is located at the tip of one arm of X and Y chromosome respectively (Wimmer et al., 2005). They have also discovered that due to lack of recombination the Y-chromosome goes through, there is a specific point in the gene where mutations accumulate (MSY) in almost all primates (Wimmer et al., 2005).

The main problem with chromosome instability produced by these breaks is the susceptibility to translocations and thus oncogene activation.

Cri-du-Chat (cat’s cry) Syndrome is a rare chromosomal disorder that is caused by the deletion of genetic material on chromosome 5. Due to this, this syndrome has an alternative name, known as 5p-, or 5p minus syndrome. Although this genetic defect is able to be diagnosed, the cause of the deletion on the chromosome is unknown. Almost all cases of the Cri-du-Chat Syndrome are found to have no relation with family members or previous generations. This syndrome is generally not inherited, as the deletion occurs randomly during meiosis (the formation of the gametes). In about 90% of people who have this condition, the deletion is completely random and is not inherited. The remaining 10% of affected people inherit a chromosome with a deleted section from an unaffected parent. This is because the parents’ balanced

The chromosomal abnormality that appears in the karyotype in Figure four is an extra chromosome 23, which happens to be an X chromosome. This abnormality originated from the mother because nondisjunction

First, the most common, which affects 75% of the population, is resulting from de novo maternal deletions involving chromosome 15q.11.2-913. Second, approximately 25% of the population results in mutations in gene encoding the ubiquitin protein ligase E3A gene. Third, there are 2-3% whom results in AS through imprinting defects. Lastly, 2% of the population results from uniparental disomy of 15q11.2-913, where the child receives two copies of a chromosome from parent and no copies from the other parent. The image below (Figure 1) shows the different genetic mechanisms that cause Angelman syndrome. We have a side-by-side visual of the chromosome and what the defect(s) look like, and where it takes place on the maternal

Affected males inherit a fragile X chromosome that had not been silenced in the previous generation by a cycle of maternal chromosome inactivation and incomplete reactivation.

Prader - Willi Syndrome is caused by the deletion or not getting Chromosome 15 from the dad. This disorder

The cause of the disorder is being born with three copies of chromosome 18 but you normally would have two copies. One symptom of my disorder is Atrial Septal Defects, these defects are the two top chambers of your heart having a hole in them. Another symptom is Cachexia this is losing muscle mass gradually. Camptodactyly and deviation of the fingers which makes them deformed. Cognitive impairment is a decline of aging, memory, judgment and more. They also have facial deformities. One facial deformity hypertelorism is having skin folds in the corner of your eyes.

Prader-Willi syndrome(PWS) is a disease caused by spontaneous genetic mutations in chromosome 15 which is evident in the early development of a fetus. Specifically, there is a deletion or a loss of genes from that chromosome. Dr. Prader, Dr. Willi, and Dr. Lambert were the first people to describe the features of PWS in 1956. Since that first time, more and more information on Prader-Willi syndrome has begun to be understood (Encyclopedia, 2016). This genetic disease is capable

The characteristics typical of Angelman syndrome derive from the "loss of function of a gene called UBE3A" which is derived from the mother (Stรถppler 2012). "People normally inherit one copy of the UBE3A gene from each parent" and both are activated in most of the body (Angelman syndrome, 2011, Genetics Home Reference). However, "in certain areas of the brain...only the copy inherited from a person's mother (the maternal copy) is active...If the maternal copy of the UBE3A gene is lost because of a chromosomal change or a gene mutation, a person will

     Mosaic Trisomy 21 happens when an egg or sperm come in with an extra copy of chromosome 21, then,