Pedigrees
A pedigree, which is also called a genealogy, can be formally defined as “a group of individuals together with a full specification of all the relationships among them” (Thompson, 1986). Pedigrees can be shown graphically. One example of a pedigree is shown in Figure 2.3. By convention we use a square to denote a male and a circle to denote a female. Horizontal lines below couples are used to represent marriages. Parents and their children are linked through vertical lines. The individuals who are in the same level in the pedigree are in the same generation, often denoted by Roman numerals. Each person in each generation is labelled by Arabic numbers. Individuals with data e.g. those who are affected by a disease, are shown by shading. By
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Pedigrees are often used to determine the mode of inheritance (e.g. dominant, recessive, etc.) of genetic diseases. They are also essential to linkage analysis.
Linkage analysis is the analysis of the linkage in the inheritance between genes at different loci based on the observational phenotypes and the known pedigree structure (Palmer, 2011). Linkage between loci is the tendency for alleles of two or more loci close on the chromosome to be transmitted to the next generation together. So generally the closer two genes lie on a chromosome, the more likely they will show linkage. Genes located on different chromosomes, for example, do not show linkage. Genetic linkage studies aim to estimate the distance between a set of markers (polymorphic DNA sequences with known location) and a putative trait gene by estimating the recombination fractions. If a disease tends to be passed to offspring along with specific markers, then it can be concluded that the gene(s) which are responsible for the disease are located close on the chromosome to these markers. The disease could be a Mendelian disease (caused by one gene) or a complex disease, which is caused by the action of many
Since the beginning of time, mankind began to expand on traditions of life out of which family and societal life surfaced. These traditions of life have been passed down over generations and centuries. Some of these kin and their interdependent ways of life have been upheld among particular people, and are known to contain key pieces of some civilizations.
Nowadays, DNA is a crucial component of a crime scene investigation, used to both to identify perpetrators from crime scenes and to determine a suspect’s guilt or innocence (Butler, 2005). The method of constructing a distinctive “fingerprint” from an individual’s DNA was first described by Alec Jeffreys in 1985. He discovered regions of repetitions of nucleotides inherent in DNA strands that differed from person to person (now known as variable number of tandem repeats, or VNTRs), and developed a technique to adjust the length variation into a definitive identity marker (Butler, 2005). Since then, DNA fingerprinting has been refined to be an indispensible source of evidence, expanded into multiple methods befitting different types of DNA samples. One of the more controversial practices of DNA forensics is familial DNA searching, which takes partial, rather than exact, matches between crime scene DNA and DNA stored in a public database as possible leads for further examination and information about the suspect. Using familial DNA searching for investigative purposes is a reliable and advantageous method to convict criminals.
Advantages of genetic testing may be helpful in determining whether or not you have a disease or are proba...
Families were essential in ancient and medieval civilizations. They were the basis of most aspects in historic civilizations. They determined who controlled different aspects of these societies, appointing leaders and rulers to govern over them; much like the familial dynasties of ancient China. They also determined the social status of individuals. Families also let to the extension of lineages, passing down values and beliefs through generations; and they also produced offspring’s that can then serve the societies in which they are born to by advancing technology and serving in their armies. Families would also be created to be merge houses, clans, and other civilizations into one. Indubitably, families were important to these ancient and
In efforts to examine how genealogy evolved into its modern manifestation, Weil’s, Family Trees: A History of Genealogy in America is a “genealogy of genealogy.” Family Trees is a study of genealogy in America and its reciprocal effects on society. Weil divides his book into four chronological regimes of genealogy in America, each presented with their own set of problems. These problems did not just disappear after each
There are many types of genetic tests that are administered to the adult population. The more commonly used genetic tests are paternity tests, genealogical tests, and forensic testing. They are quite self-explanatory; paternity tests are to determine relatedness of 2 subjects, genealogical tests are used to formulate a heritage or ancestry, and forensic testing is used to identify or rule out a person that has been charged with a crime. Other genetic tests include presymptomatic testing, used to determine the risk someone has to developing a genetic disorder, diagnostic screening, used to rule out or identify a suspected condition, and carrier screening, used to determine if an individual carries one copy of a gene mutati...
Family history possesses valuable information about a person’s past and future life. It can be used as a powerful screening tool to help conduct decisions about genetic testing for you and family members at risk. Family history can identify potential health problems that an individual has an increased risk for in their lifetime. With early identification, you can begin taking steps to reduce the risk with things such as lifestyle changes of diet and exercise. In many cases, just by adopting a healthier lifestyle can reduce your risk for diseases that run in your family.
A genogram is a pictorial display of a person's family relationships and medical history. According to (Hawley,D.R. & Geske,S.2000) a genogram goes beyond a traditional family tree by allowing the user to visualize hereditary patterns and psychological factors that punctuate relationships. It can be used to identify repetitive patterns of behavior and to recognize hereditary tendencies. According to (Working together in children’s services, 2008) Having some awareness and knowledge of a dysfunctional family links in closely with understanding the impact of the relationships within it, if we consider Bowens theory around the family, I found information regarding his thoughts and views and how they can be useful in social work
Genograms are key to helping you determine the patterns and differences that are consistent in your family structure. Genograms can also help you to determine why certain subsystems engage in certain behaviours.
Conclusion: Inheritance is the means by which certain traits are passed down from one generation to the next. By applying Mendel’s law of dominance it is possible to choose genetic traits in parents to produce offspring that carries the desired trait. It is also beneficial in determining the likelihood of passing down genetic diseases from one generation to the next. However environmental factors and mutations can increase or decrease the probability of inheriting particular genes.
The higher accuracy of the prediction with CNP information might also result in smaller mean squared errors of prediction (Table 4)’. On the other hand, the authors found that linkage disequilibrium (LD) between SNP and CNP was not much different from that between two SNPs. The authors demonstrated that an increased mutation rate and larger number of segregating alleles hardly affects LD with a nearby SNP. I have the following comments. 1)
National Institute of General Medical Sciences. (2010). "21st-Century Genetics." The New Genetics, p. 74-83. Retrieved from http://publications.nigms.nih.gov/thenewgenetics/chapter5.html
Genetics play an important part in the development of type 1 and type 2 diabetes. The most common of the two types of diabetes is type 2. Type 2 diabetes is being observed in the younger generation. It has becoming increasingly common in younger children, but the genes that are responsible for causing it are scarcely defined.("Genetic Factors in Type 2 Diabetes") What we do have well knowledge of is that the disease is a result of one gene mutating. In type 2 diabetes many genes are said to be involved in the developing of the disease, we just are not sure which gene it is that is being mutated.(1,4) However, the risk of having the disease is affected by your siblings or parents having it. Immediate relatives to individuals with type 2 diabetes are at higher risk of getting the condition rather than a person with no relative with diabetes. If the mother of the father has diabetes then the grandchild has a fifteen percent risk of having type 2 diabetes, but if both the father and the mother of the offspring have diabetes then the offspring's risk would increase by seventy-five percent chance of being affected with the condition. On the other hand, if the offspring were to have a sibling that was a non-identical twin with diabetes it would have a ten percent chance of being affected, but if it had an identical twin the risk would increase by ninety percent. Type 2 diabetes is known to run in families, but as to how it is inherited is not really specified. Scientists think that some environmental factors act as accelerators to diabetes, increasing the development. Some genes, known as susceptibility genes increases the risk of developing diabetes to individuals that carry the genes. ("Diabetes and Genetics") A way to find this gen...
Molecular Diagnostics is defined as tests which identify certain patterns in both RNA and DNA. These tests are able to identify RNA, genes, and protein sequences which play a role in diseases. These sequences may be linked to diseases which include nucleotide polymorphism, deletions, rearrangements, and many more. Molecular Diagnostics is also able to identify and multiply the presence of certain microorganisms and cells. Molecular Diagnostics provides a great amount of clinical information. For example, hereditary disorders to specific drug therapies or hereditary relationships in general. Molecular Diagnostics is also well known for providing qualitative and quantitative results that help in detection,
The first category I will start with is consanguinity. These are the people who are biologically related to each other. When a family is biologically related, people say there is a deeper connection to one another. They are related by blood. Children who are blood related to their parents are said to have more protective and strict parents. Parents are a huge part of family because they protect and raise their kids. While parents are very important so are sisters and brothers. While the parents are away the older sister can take care of the younger and vi...