BME 80H Lecture Notes - Lecture 6: Middle Ages, Thrombus, List Of Rabbit Breeds
4 Jun 2018
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Lecture #6- Pedigree Analysis of Human Genetic Traits (chapter 3 p.
58-61/56-59, chapter 4 all, chapter 10, p. 226-230/223-228)
I. Human Pedigree Charts!
A. Symbols and terms used (figure 3.16/3.14, definitions list)
B. Example (figure 3.17/3.15) C. Uses
Genetic Counselors do the analysis and meet with the families. II.
Pedigree Analysis
A. Mendelian Inheritance in Humans (link OMIM)
B. The main things that are examined in the pedigrees are whether the
trait is:
1. Dominant or recessive!
2. Carried on an autosome, sex chromosome or in mitochondria
C. Modes of Inheritance
Autosomal recessive Autosomal dominant X-linked recessive X-linked
dominant Y -linked Mitochondrial
III. Inheritance patterns (depicted in pedigrees) for human traits
affected by a single gene
A. Autosomal Recessive Traits: only homozygous recessive individuals
display the trait
1. Patterns of inheritance:
2. Pedigree (figure 4.2)
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3. Examples (table 4.1)
a) Cystic fibrosis:
symptoms and prognosis (figure 4.3):
population most affected:
Cytogenetics (Handout)
Gene Product= cystic fibrosis transmembrane conductance
regulator (CFTR) (figure 4.5)
Biological basis of the phenotypes/symptoms (Handouts):
Balanced Polymorphism/Heterozygous advantage:
•Carrier (heterozygote is protected against
•Typhoid Fever- S. Typhic cannot enter the cells as well
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•Cholera toxin- when it binds to cells lining the intestine, it causes the cells
to open and the chloride ions exit, along with Na+ and H2O, creating a huge
water loss (about 1L/hr). With mutant CFTR, toxin does not bond
b) Sickle Cell Anemia
Symptoms and prognosis (figures 10.13):
•Sickled red blood cells
-Fragile & break
-Block capillaries, disrupting blood flow to tissues
-Sickling crisis—> PAIN
•Can be lethal in childhood
•Bone Marrow transplant = cure
•Life expectancy= 40-60 years
population most affected:
•West African extraction, parts of Greece, South AMerica, India, Italy, etc.
•1/500 births in U.S. black population
Biology (figures 10.9, 10.14, 10.15 animation at http://
www.dnalc.org/view/15532-Sickle-cell-anemia- 3D-animation-
with-narration.html)
•Mutation in Hemoglobin gene (HbS)
•Hemoglobin (Hb) is the oxygen carrying molecule in RBC’s.
find more resources at oneclass.com
find more resources at oneclass.com
