INHERITANCE GENES
Genetic terminology
Locus The location of a
gene on a chromosome
Allele The particular form of the gene inherited from
mum 1 dad
Dominant One copy of the gene causes disease
Recessive Both copies required for disease to occur
Homozygous Identical alleles
Heterozygous Different alleles
Genotype Genetic makeup of an individual
Phenotype Physical expression ofgenotype
The
majority of pts do not
get sick from monogenic
disease
Polygenic disease consists of
complex changes in the genome that
9 the risk of developing disease
T2 D M Cancer
Asthma Hypertension
Modes of inheritance
A Autos omnal dominant 7 One mutation in one allele
can cause disease Inherited breast cancer
E.g
, Familial hyper cholestrolaemia Neurofibromatosis
No carriers in autosomnal dominant
SO offspring are affected
Male Female
Transmission between all sexes
Does not skip generations
Denovo spontaneous mutations
Penetrance can be loot
Punnet square
Pedigree
Symbols
Vertical degree
Pattern with
multiple generations
affected usually indie
have an affected parent
Either sex can be affected and transmit disorder
On average SOX of offspring will be affected
Auto somnal dominant disease mechanism
Genetic terminology
Locus The location of a
gene on a chromosome
Allele The particular form of the gene inherited from
mum 1 dad
Dominant One copy of the gene causes disease
Recessive Both copies required for disease to occur
Homozygous Identical alleles
Heterozygous Different alleles
Genotype Genetic makeup of an individual
Phenotype Physical expression ofgenotype
The
majority of pts do not
get sick from monogenic
disease
Polygenic disease consists of
complex changes in the genome that
9 the risk of developing disease
T2 D M Cancer
Asthma Hypertension
Modes of inheritance
A Autos omnal dominant 7 One mutation in one allele
can cause disease Inherited breast cancer
E.g
, Familial hyper cholestrolaemia Neurofibromatosis
No carriers in autosomnal dominant
SO offspring are affected
Male Female
Transmission between all sexes
Does not skip generations
Denovo spontaneous mutations
Penetrance can be loot
Punnet square
Pedigree
Symbols
Vertical degree
Pattern with
multiple generations
affected usually indie
have an affected parent
Either sex can be affected and transmit disorder
On average SOX of offspring will be affected
Auto somnal dominant disease mechanism
