Showing posts with label Genetics. Show all posts
Showing posts with label Genetics. Show all posts

Monday, 25 July 2022

What is Factor-V gene mutation?

What is Factor-V?

        Blood clotting is a multi-step process which involves many proteins. Factor V is one of such protein. This protein is also known as labile factor, and which is derived from liver and platelets. Factor-V helps in the conversation of prothrombin to thrombin which is one of the vital steps in the blood clotting cascade. 

Difference between Factor-V and Factor-V Leiden

        Factor-V is one of the proteins involved in blood clotting and Factor-V Leiden is the mutation or gene change which produces in the abnormal blood clots.

Factor-V Leiden

        This is a genetic disorder, and which develops abnormal clots (thrombosis) mostly in legs called deep vein thrombosis (DVT). If this clot moves to lung through bloodstream and blocks the blood flow in lung, this condition is called as pulmonary embolism (PE) which is a lethal condition.
        The clotting activity of Factor-V is controlled by activated protein C (APC), which turn off Factor-V to prevent blood clotting. But APC cannot work with Factor-V Leiden which lead to abnormal blood clotting. Hence, this Factor-V Leiden is also known as APC resistance. Factor-V Leiden mutation results from the G to A transition in 1601 position of nucleotide (c.1601G>A). This transition results in arginine to glutamine substitution (p.Arg534Gln) at amino acid 534 of protein.

Diagnosis of Factor-V Leiden

        If you have a family history of thrombosis or if you are experiencing unnecessary blood clots or to know the inherited risk of having this mutation or if you are having DVT during pregnancy, the doctor suggests getting tested for Factor-V mutation. A simple blood test can be done by polymerase chain reaction to find out the mutation.

Genetics in Factor-V Leiden

        This is an autosomal dominant disorder means one copy of the mutated gene can cause the increased risk of thrombosis. 
  • Factor-V Leiden heterozygous condition (GA, one variant) - having one mutated gene inherited from one parent and one normal gene from another parent.
  • Factor-V Leiden homozygous condition (AA, two variants) - having two mutated gene inherited from both parents. No normal factor-V gene is present.
  • GG, Leiden mutation is absent.
        Heterozygous condition increases the risk of developing abnormal clots whereas having homozygous condition makes the situation worse means higher the chances of producing clots.

References

  • Factor V Leiden - Symptoms and causes. (2020, August 1). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/factor-v-leiden/symptoms-causes/syc-20372423#:%7E:text=Factor%20V%20Leiden%20(FAK%2Dtur,Leiden%20never%20develop%20abnormal%20clots.
  • Kirshman, M. (2019, November 22). Factor V Leiden Mutation and PT 20210 Mutation. Testing.Com. https://www.testing.com/tests/factor-v-leiden-mutation-and-pt-20210-mutation/.
  • Hanna Rennert PhD, Robert A. DeSimone MD, in Transfusion Medicine and Hemostasis (Third Edition), 2019

Hope this information helps you!


Saturday, 25 June 2022

What is inside a chromosome?

We have already studied the definitions of chromosome, genome, and DNA in the previous blogs. Now, let us have a look on what is there inside the chromosome.

Each human cell contains 46 chromosomes except eggs and sperms, and which is present inside the nucleus. 23 chromosomes come from the father and other 23 chromosomes from the mother. The DNA associated with histone proteins are wrapped inside the structure called chromosome and it is replicated in the time of cell division. These chromosomes are visible under microscope only during the cell division! 

Why the DNA packaging is so important? Chromosome has plethora of genetic information which stored in DNA. If the DNA present in a cell uncoil, it comes to six feet long!

 Related Terms:

  • Histone - These are the proteins which helps the DNA packaging inside the cell's nucleus. Moreover, which helps the DNA to condenses in chromatin. These proteins are rich in lysine and arginine. 
  • Nucleosome - It is the repeating unit of chromatin. DNA along with histone proteins form nucleosome. The core histones such as H3, H4, H2A and H2B form H3-H4 tetramer and H2A-H2B dimer. The negatively charged DNA wraps around the positively charged histone octamer. As an outcome, the nucleosomes are stabilized. 
  • Chromatin - Nucleosomes packed together to form chromatin. The chromatin loops fold around each other to form chromosome.
  • Centromere - The structure which holds the sister chromatids together. Each chromosome has two p and q arms which held together by centromere.
  • Telomeres - The repetitive sections of DNA present at the end of each eukaryotic chromosome, which plays a vital role in chromosome replication and maintenance. Telomeres protect the chromosome from becoming impaired. During each cell division, some part of telomeres may lose in some of the cells. If the telomeres completely gone, the cell dies.

References:

  • The Jackson Laboratory. (n.d.). Minute to Understanding: What is a chromosome? https://www.jax.org/news-and-insights/minute-to-understanding/what-is-a-chromosome.
  • What is a chromosome? (2016, January 25). Yourgenome. https://www.yourgenome.org/facts/what-is-a-chromosome.
  • NHGRI. (2019, March 9). Chromosomes Fact Sheet. Genome.Gov. https://www.genome.gov/about-genomics/fact-sheets/Chromosomes-Fact-Sheet.


Thank you!

Thursday, 2 June 2022

Genetics and its divisions

Genetics

Genetics is the study of genes and heredity. It also deals with how the traits or certain characteristics are being passed to offsprings from parents. Gene is the basic unit of heredity, and it is the part of DNA which has the information for protein synthesis. The entire set of genes in an organism is called genome. The genome is present in the nucleus in the case of human, animal and plant cell.

Genetics plays a major role in disease diagnosis, personalized treatment for diseases and to identify the likelihood of getting a particular ailment. This all can be understood based on the genetic information. Any changes in the gene can prevent the certain protein synthesis which affect the specific functions. Genome sequencing technology is being used to identify the changes in the gene, and this information can be used for the betterment of human life.

Divisions

Primarily, there are 3 following subdivisions for genetics.

  • Transmission genetics (Classical genetics)
  • Molecular genetics
  • Population genetics
Transmission genetics deals with how the genes are being transferred from one generation to other generation. It mainly focuses on an individual's genetic make up and how it inherits to the following generation. Molecular genetics emphasis on the structure and function of gene. It includes processes such as replication, transcription, translation and gene regulation. Whereas, population genetics studies the genetic makeup of individual members of the same species. It mainly deals with the evolution that is how the genetic make is being changed over time and space.

Other branches of genetics

  • Microbial genetics - The study of genetics of microorganisms such as bacteria, viruses, unicellular plants and animals
  • Immunogenetics - The study of the effect of genes on immune response
  • Behavioral genetics - The study of the impact of genetic composition on one's behavior
  • Human genetics - The study of human hereditary processes and inheritance
  • Animal genetics - The study of genes and heredity in animals
  • Plant genetics - The study of genes and heredity in plants
  • Viral genetics - The study of genetics of viruses
  • Cytogenetics - The microscopic study of chromosomes to understand the changes in the chromosome like extra or missing chromosome, broken etc. which lead to genetic diseases
  • Clinical genetics - The study of causes and inheritance of genetic disorders

References
  • Winchester, A. (2020, May 15). genetics. Encyclopedia Britannica. https://www.britannica.com/science/genetics.
  • Branches and Importance of Genetics, study&Score. (n.d.). STUDYANDSCORE. https://www.studyandscore.com/studymaterial-detail/branches-of-genetics-importance-of-genetics
  • Genetics. (2000). NIGMS. https://www.nigms.nih.gov/education/fact-sheets/Pages/genetics.aspx.
  • Genetics, A Conceptual Approch by Benjamin.A.Pierce
               
                Hope you all like the information!
T             Thank you!😊

Monday, 4 April 2022

Basic terms used in Genetics

  1. Chromosome - These are the structures that hold genetic information. There may be single chromosome as in bacteria or multiple chromosomes as in eukaryotic organisms.
  2. Gene - It is unit of information that encodes a genetic characteristic. And it is the fundamental unit of heredity.
  3. Allele - Different forms of a gene that occurs at the same locus on homologous chromosomes.
  4. Trait - Certain characteristic of an individual that is inherited.
  5. Genotype - Genetic constitution of an individual.
  6. Phenotype - The observed characteristics of an individual.
  7. Genome - The entire genetic material of an organism.
  8. Locus - Location of a specific gene or a DNA sequence on a chromosome.
  9. Homologous chromosomes - Chromosomes that are identical to each other in morphology (shape and structure) and genetic constitution (same gene sequence, centromere location, loci and chromosome length). A pair of homologous chromosome consists of chromosome from father (paternal) and chromosome from mother (maternal).
  10. Homozygous - Similar alleles of a gene is present in the specific locus of a pair homologous chromosomes.
  11. Heterozygous - 2 different alleles of a gene are present in the specific locus of a pair of homologous chromosomes.
References:

  • P.Arora, M. (2005). Genetic Engineering (1st ed.). Himalaya Publishing House.
  • Glossary of Genomics Terms. (2013, April 10). Genetics and Genomics | JAMA | JAMA Network. https://jamanetwork.com/journals/jama/fullarticle/1677346.

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