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GENETIC POLYMORPHISM SALWA HASSAN TEAMA

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GENETIC POLYMORPHISM

GENETIC POLYMORPHISMSALWA HASSAN TEAMA

HUMAN GENETIC VARIATION

Difference and variation of genetic make up among individuals.

Genetic polymorphism promotes diversity within a population.

Genetic polymorphism: A difference in DNA sequence among individuals, groups, or populations.

The DNA of most people is 99.9% the same. Although we are look quiet different from one another.

DNA and Human Diversity

Genetic Polymorphism.

www.centenary.eduA genetic polymorphism is the existence of two or more variants - which may be allelic, phenotypic, chromosomal or general DNA sequence variants - at significant frequencies in a population. A frequency of 1% or more is generally considered to be a polymorphism.

Source: Wikipedia

Source of Genetic Variation

SOURCE OF GENETIC VARIATION

www.bmj.com

SINGLE NUCLEOTIDE POLYMORPHISM

The quality of existing in several different forms

SNP is a source variance in a genome. SNPs are the most simple form and most common source of genetic polymorphism in human genome (90% of all human DNA polymorphism).

SNPs begin their existence as point mutations (nonsense mutation).

Two types of nucleotide base substitutions resulting in SNPs:Transition: Substitution occurs between purines or pyrimidines. Account 2/3 of all SNPs.Transversion: Substitution occurs between purines and a pyrimidines.

Single Nucleotide Polymorphism

DISTRIBUTION OF SNPS

CODING REGION SNPS

PHENOTYPE, GENOTYPE AND HAPLOTYPE

mics.org

INSERTION/DELETION POLYMORPHISMIndel, is a type of genetic variation in which a specific nucleotide sequence is present (insertion) or absent (deletion). While not as common as SNPs, indels are widely spread across the genomeAn indel in the coding region of a gene that multiples of 3 nucleotides result in a protein with extra amino acids (insertion) or loss of amino acids (deletion) or is not a multiple of 3 nucleotides results in a frameshift mutation; shifting the reading frame and the DNA transcript sequence may now code for an entirely different set of amino acids or result in a premature stop codon, altering the protein structure and function.

Source: http://link.springer.com/referenceworkentry/10.1007%2F978-1-4419-1005-9_706

SEQUENCE REPEATS

RECOMBINATION

RECOMBINATION

Homologous recombination; the process of genetic exchange that occurs between any two molecules of DNA that share a region (or regions) of homologous DNA sequences. Occurs frequently while sister chromatids are paired during meiosis, it generally involves exchange of large regions of the chromosomes.

Site specific recombination involves exchange between much smaller regions of DNA sequence (approximately 20 - 200 base pairs), events occur primarily as a mechanism to alter the program of genes expressed at specific stages of development.The most significant site-specific recombinational events in humans are the somatic cell gene rearrangements that take place in the immunoglobulin genes during B-cell differentiation in response to antigen presentation.

DNA Transposition is a unique form of recombination where mobile genetic elements can virtually move from one region to another within one chromosome or to another chromosome entirely. Transposition occurs with a higher frequency in bacteria and yeasts than it does in humans.

Pharmacogenomics The science of understanding the correlation between an individual patient`s genetic make-up (genotype) and the their response to drug treatment.SNP Diagnostics ;SNPs in Functional Proteomics;SNPs and precancerous conditions and cancer susceptibility ;GeneTherapy

GENETIC VARIATION AND HUMAN DISEASES

In certain parts of Africa, however, the same allele is polymorphic because it confers resistance to the blood-borne parasite that causes malaria.ALLELE OF SICKLE-CELL DISEASE

MUTATION OR POLYMORPHISM

Use and Importance of SNP

Ali Khalifa. Applied molecular biology; eds: ( Fathi Tash and Sanna Eissa). 109 pages. Egypt. University Book Center. 2002. Daniel H. Farkas. DNA Simplified: The Hitchhiker's Guide to DNA. 110 pages. Washington, DC: AACC Press, 1996, ISBN 0-915274-84-1. Available in paper copy from the publisherInnis, David H. Gelfand, John J. Sninsky. PCR Applications: Protocols for Functional Genomics: 566 pages. Academic Press; 1 edition (May 17, 1999). ISBN:0123721865. Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter. Molecular Biology of the cell. 1392 pages. Garland Science; 5 edition (November 16, 2007).ISBN. 9780815341055. Robert F. Mueller, Ian D. Young. Emery's Elements of Medical Genetics: Publisher:Churchill Livingstone. 1995 ISBN. 044307125X. Robert F. Weaver. Molecular Biology. 600 Pages. Fourth Edition. McGraw-Hill International Edition. ISBN 978-0-07-110216-2. William B. Coleman, Gregory J. Tsongalis . Molecular Diagnostics. For the Clinical Laboratorian: 592 pages. Humana Press; 4th Printing. edition (August 15, 2005). ISBN 1588293564http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/GP/Relationship.htlhttp://www.ornl.gov/sci/techresources/Human_Genome/faq/snps.shtmlhttp://genome.wellcome.ac.uk/doc_wtd020780.htmlhttp://hapmap.ncbi.nlm.nih.gov/whatishapmap.htmlhttp://medicine.jrank.org/pages/1921/Balanced-Polymorphism.htmlREFERENCES &FURTHER READING

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