Because learning changes everything.(R)
Chapter 13
Mutations and Genetic
Testing
Essentials of Biology
SEVENTH EDITION
Sylvia S. Mader
Michael Windelspecht
(C) McGraw Hill LLC.Rheumatoid arthritis
o Immune system destroys person's own body
o Inject adenoviruses that contain anti-inflammatory genes into the
affected joint
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2Figure 13.10 Use of a DNA Microarray to Test
for Mutated Genes
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DNA Sequencing
o Individual's complete genome
o Important in personalized medicine
o Can not only show risk for disease but also holds key to
new treatment options
o Based on genetic information, it is possible to improve
patient outcomes and increase treatment options with
increased precision
o Becoming more affordable leading to popularity of
personalized medicine
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Testing the Fetus
Ultrasound--helps evaluate fetal anatomy for serious
abnormalities
o Uses high-frequency sound waves
Testing fetal cells
o Cells from amniocentesis or chorionic villus sampling
o Fetal cells can also be collected from mother's blood
o PCR used to amplify DNA, no risk to fetus
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Testing the Embryo
o Testing the embryo--
following IVF, one cell
can be removed from
embryo without harm
Access the text alternative for slide images.Inv dup 15 syndrome--inverted duplication of chromosome 15
o Inversion--segment joins in direction opposite from normal
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Chromosomal Mutations- Translocation
Rearrangement of parts between
nonhomologous chromosomes.o Alignment only possible when the inverted chromosome forms a loop
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Genetic Testing
Genetic counseling--potential parents are advised on their risk of
inherited disorders
Counselor helps couple understand the mode of inheritance,
medical consequences of disorder, and decisions they might wish
to make
Karyotyping--visual display of chromosomes arranged by size,
shape, and banding pattern.(C) McGraw Hill LLC
Kateryna Kon/Shutterstock 15
Testing for a Protein
Some disorders are caused by a missing enzyme
o Test for quantity of enzyme produced
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Testing the DNA- Genetic Markers
Relies on an abnormality in the DNA sequence due to presence of
abnormal allele.(C) McGraw Hill LLC
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In Vivo Gene Therapy
Cystic fibrosis treatment
o Gene needed is sprayed into the nose or delivered to lower respiratory
tract
o Use adenoviruses or liposomes to carry gene
Poor coronary circulation treatment
o Vascular endothelial growth factor can cause growth of new blood
vessels.(C) McGraw Hill LLC
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Ex Vivo Gene Therapy
Treatment of SCID
o Severe combined immunodeficiency
o Lack enzyme involved in the maturation of cells producing
antibodies
o Bone marrow stem cells are removed and infected with RNA
retrovirus carrying the gene for normal enzyme.o Williams syndrome--chromosome 7 loses a tiny end piece
o Cri du chat--chromosome 5 loses an end piece
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Chromosomal Mutations- Duplication
Chromosome segments are repeated
Individual has more than two alleles for certain traits.5% of Down syndrome cases caused
by a translocation in previous
generation between chromosomes
21 and 14
o Not related to parental age but is
inherited
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Chromosomal Mutations- Inversion
A chromosome segment is turned 180?o Small portion of liver is removed and infected with retrovirus
containing normal cholesterol receptor
o Tissue is returned to patient
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Figure 13.13 Ex Vivo Gene Therapy in Humans
Access the text alternative for slide images.(C) McGraw Hill LLC
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Gene Mutations
Gene: A segment of DNA that encodes for a functional product, typically a
protein, crucial for cellular functions.Figure 13.9 Use of a Genetic Marker to Test for a Genetic Mutation
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Testing the DNA- DNA Microarrays
Mutant alleles placed onto a DNA microarray, small silicone chip which is
compared to DNA of a person to indicate risk of developing disease,
which can be discussed with genetic counselor.Include deletions, duplications, inversions, and
translocations.All rights reserved.2.3.4.?