L3: Modes of Inheritance Flashcards
Modes of Inheritance
- Mendelian inheritance (single gene traits)
- Multi-factorial inheritance
- Non-traditional inheritance
Def of Mendelian Inheritance (Single Gene Traits)
- The inheritance of single-gene disorders
Def of Locus
Specific position of gene on the chromosome
Def of Alleles
Introduction to Genetic Pedigree
Types of Mendelian Inheritance
Def of AD Inheritance
Risk of Transmission in AD Inheritance
Rules of AD Inheritance
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Sex affected in AD Inheritance
Male & Female are affected in equal proportion
Generations affected in AD Inheritance
- Transmitted from one generation to the next
- Sporadic cases with high paternal age suggest new mutation
Transmission between sexes in AD Inheritance
- All forms of transmission between sexes are observed (male to male - male to female // female to female - female to male)
- Male to male transmission exclude the gene on X chrom
Examples of AD Inheritance
Sporadic cases with AD disorders suggest โฆโฆ..
New Mutation
Male to Male transmission exclude โฆโฆ..
X-Linked Inheritance
Def of AR Inheritance
Risk of Transmission in AR Inheritance
Sex affected in AR Inheritance
Male & Female are affected in equal proportion
Generations affected in AR Inheritance
Affected individual usually only in a single generation
Consanguinity supports โฆโฆ.
AR Inheritance
Examples of AR Inheritance
Factors affecting AD Gene Expression
- Pleiotropy
- variable Expressivity
- Reduced penetrance
- New Mutations
Def of Pleiotropy
A single gene (AD) that may give rise to two or more apparently unrelated effects.
Etiology of Pleiotropy
- Different mutations in the same gene