Download Genetics of prokaryotic cell

Basic types of
genetic diseases
Marie Černá
Lecture No 423-Heredity
Haploid and Diploid Cells
Germ-line and Somatic mutations
Genetics counseling
Pedigree
Genetics counseling
Pedigree symbols
Genetics counseling
Pedigree
Classification of
genetic disorders
 Single-gene disorders
 Chromosome disorders
 Multifactorial disorders
Classification of
genetic disorders
 Somatic cell mutations - cancer
familial predisposition is passed through germ-line cell
 Mitochondrial mutations
Frequency of congenital genetic diseases (%)
Single gene:
AD
AR
X-linked
Total single gene
Chromosomal
Multifactorial:
0.14
0.17
0.05
0.36
0.60
congenital
others
Total multifactorial
Unclassified genetic
2.30
2.40
4.70
0.12
Total genetic
5.78
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Thompson 1991
Multifactorial disorders
 environmental factors
 allele polymorphism
- predisposition
- protection
Chromosome disorders
 chromosome mutations
 genome mutations
cytogenetics
Single-gene disorders
 with classical Mendelian inheritance
 with non-Mendelian inheritance
- imprinting errors
- dynamic mutations
- uniparental disomy
molecular genetics
Characters qualitative
Characters quantitative
distribution is discontinuous
(phenotypic categories)
distribution is continuous
(Gaussian distribution)
monogenic heredity
polygenic heredity
additive effect of genes –
application of threshold
analysis of heritability in
offspring of particular parents
by assignment of ratios
analysis of heritability
at the level of population
by statistic methods
minor effect of environment
major effect of environment
Expressivity
The extent to which a genetic defect is
expressed:
- quantitative (hemophilia)
- qualitative (Marfan syndrome)
If there is variable expressivity, the trait may
vary in expression from mild to severe but is
never completely unexpressed in individuals
who have the corresponding genotype.
Penetrance
The fraction of individuals
with clinical signs of the disease
from the group of all carriers of genotype,
which causes this disease.
Human genetics – Medical genetics
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Genetics counseling – pedigree analyses
Clinical genetics – morphology analyses
Cytogenetics – chromosome analyses
Molecular genetics – DNA analyses
Biochemical genetics – protein analyses
Developmental genetics – ontogenesis
Population genetics – gene pool studies