Finding New Facts About Genetic Mutation by student19

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									Finding New Facts About
    Genetic Mutation


           SeRa Kim
        What is Genetic Mutation?
 In biology, mutations are changes to the
  genetic material (usually DNA or RNA).
  Mutations can be caused by copying errors
  in the genetic material during cell division
  and by exposure to radiation, chemicals
  (mutagens), or viruses, or can occur
  deliberately under cellular control during
  processes such as meiosis or
  hypermutation.
        Types of Mutations

Single base substitutions
Insertions and deletions
Chromosomal mutations
        Single Base Substitutions
 A single nucleotide base becomes replaced
  by another. These single base changes are
  also called point mutations.
         •
         Insertions and deletions
 Extra base pairs may be added or deleted
  from the DNA of a gene.
               Chromosomal mutations
 Translocations - Translocations are the transfer of a piece of one
  chromosome to a non-homologous
 Inversion - A region of DNA on the chromosome can flip its
  orientation with respect to the rest of the chromosome.
 Deletions - A large section of a chromosome can be deleted resulting
  in the loss of a number of genes.
 Duplications - In this mutation, some genes are duplicated and
  displayed twice on the same chromosome.
 Chromosome non-disjunction - During cell division, the
  chromosomes fail to successfully separate to opposite poles, resulting
  in one of the daughter cells having an extra chromosome and the
  other daughter cell lacking one.
                       Cystic Fibrosis
 Cystic fibrosis (CF) is a disease that causes the body to make thick,
  sticky mucus (say: myoo-kus). This causes problems in two major
  areas: the lungs and the digestive system.




                                            mucus plug in appendix
                   Down Syndrome
 Down syndrome or trisomy 21 is a genetic condition
  resulting from the presence of all or part of an extra 21st
  chromosome. Down syndrome is characterized by a
  combination of major and minor abnormalities of body
  structure and function. Among features present in nearly
  all cases are impairment of learning and physical growth,
  and a recognizable facial appearance usually identified at
  birth. It is named after John Langdon Down, the British
  doctor who first described it in 1866.
DS is the commonest chromosomal anomaly with an incidence of about 1:700
live births.It includes a phenotype with mental retardation; characteristic facies
with oblique eye fissure, epicanthus, flat nasal bridge, protruding tongue (figs
1a and 1b); short broad hands and wide space between first and second toes
(figs 2 and 3); hypotonia and other associated congenital anomalies and
developmental disorders.
                      Haemophilia
 Haemophilia or hemophilia is the name of any of
  several hereditary genetic illnesses that impair the body's
  ability to control bleeding. Genetic deficiencies (or, very
  rarely, an autoimmune disorder) cause lowered plasma
  clotting factor activity so as to compromise blood-clotting;
  when a blood vessel is injured, a scab will not form and
  the vessel can continue to bleed excessively for a very
  long period of time. The bleeding can be external, if the
  skin is broken by a scrape, cut or abrasion, or it can be
  internal, into muscles, joints or hollow organs. It might
  therefore present visibly as skin bruises, or subtly as
  melena, hematuria, or bleeding in the brain.
                      Huntington’s Disease
   Huntington's disease (HD, also Huntington disease), formerly
    known as Huntington's chorea, is a rare inherited genetic disorder
    characterized by abnormal body movements called chorea, and a
    reduction of various mental abilities. It takes its name from the Ohio
    physician George Huntington who described it precisely in 1872.




Cross section of a brain of an adult
with Huntington disease,
illustrating marked striatal atrophy.

								
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