01:119:115 Lecture Notes - Lecture 18: Aneuploidy, Meiosis, Achondroplasia
7 May 2018
School
Department
Course
Professor
Human Genetics
I.
Apply, interpret pedigree
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Traits with Mendelian Inheritance
II.
CC Recessive, dominant disorders
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Traits with Non-Mendelian
III.
CC Types of disorders
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Genetic Testing
IV.
CC Types of Tests
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ID: interpret, execute & diagnose a pedigree
ID and compare/cc recessive and dominant disorders
ID & CC disorders related to chromosome number alternation
ID & CC disorder related to chromosome structure alternation
CC genetic testing methods
Human Genetics:
I.
Intro:
A.
Study of inherited variance in humans
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Few offspring
○
Long generations
○
Can't experiment on humans
○
Difficulties in studying human genetics
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Population of large extended families
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Analyze makings that have already occurred, rather than manipulating
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Medical attention to human genetic diseases
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"Natural experiment" - how Garrod figured out that Mendel's rules apply to humans
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How to study human genetics:
Can also use DNA sequencing
Many generations extended relatives ---> genetic basis of similarities & difference
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European royal family
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Prominent from 1100s to 1780s (or 1918)
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Detailed records of matings & phenotypes (i.e hemophilia)
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X linked recessive disorder
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Pedigree Analysis
B.
Historical Example: Habsburgs
Lecture 18 Human Genetics
Sunday, November 5, 2017
1:13 AM
18 Human Genetics Page 1
Pedigree :Family tree that shows inheritance patterns over several generations
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Can determine inheritance pattern(dominant recessive)
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Based on prevalence & distribution of trait
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Often used by genetic counselors
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Human traits with Mendelian Inheritance:
II.
In genes…
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18 Human Genetics Page 2
In genes…
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Recessively Inherited Disorders:
A.
Dominant allele makes enough protein
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Autosomal recessive:
Heterozygote = carriers (don't have the gene)
Most human genetic disorders are single-locus autosomal recessive traits
To have disorder…
Must be homozygous recessive
2 copies of defective allele required
Parents of most affected individuals are carriers:
Defective chlorine channel
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Most common lethal genetic disease in us
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1/~2500 people of European decent affected (frequency = ~ 0.004)
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~4% carriers
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Multiplication rule: 0.04 x 0.04 = 0.0016 = 0.0016 freq. of carriers mating
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0.0016/4 (probability) = 0.0004 = 0.0004 frequency affected
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Ex: Cystic Fibrosis
18 Human Genetics Page 3
