Inheritance patterns Flashcards
what are the 3 mendelian laws
Dominance
Segregation
Independent assortment
Autosomal is
a)all chromosomes excluding sexchromosomes
b) sex chromosomes
a
what is mendelian inheritance
a) autosomal, sex linked, dominant, recessive
b) imprinting, mitochondrial inheritance, multifactorial, mosaicism
a
Define homozygous and hetrozygous
Homo= presence of identical alleles at locus
Hetro= presence of 2 different allies at given locus
Define allelic heterogeneity
Mutations within same gene cause same clinical condition (like CF)
what is the most common autosomal recessive condition on the UK
Cystic fibrosis
which gene Is affected in cystic fibrosis
CFTR
what is consanguinity
Reproductive union between 2 relatives
Define autozygousity
Homogyzosity by decent (inheritance of same altered allele through 2 branches of same family) (consanguinous )
A carrier (asymptomatic) individual with regards to an autosomal recessive condition has what % chance of having affected offspring
25%
Define autosomal dominant inheritance
Disease/condition manifests in heterozygous state
are men and women affected differently or equally in Autosomal Recessive conditions
equally
Are men and women affected differently or equally in autosomal dominant condiments
equally
Define penetrance
% of people with specific genotype showing expected phenotype
Define expressivity
Range of phenotypes expressed by a singe genotype
What is anticipation
Autosomal dominant Genetic disorder affects successive generations early or more severely
Define gonadal mosaicism
When there are 2 different populations of cells in the gonads. One population is normal and the other is mutated. All gametes from the mutated line are effected.
Define sex limiting
A condition that affects one sex more than the other (such as BRCA1/2 beast cancer in women)
What is X-linked
Genes carried only on the X chromosome
Usually only males affected
Transmitted (usually) through unaffected females
No male-to-male transmission
define Lyonization
One of the female X chromosomes becomes inactivated early in embryogenesis.
what type of inheritance pattern is Duchenne muscular dystrophy
X linked
define Homoplasmy
a eukaryotic cell whose copies of mitochondrial DNA are all identical (identically normal or have identical mutations)
are Mitochondrial DNA inherited from mother or father?
mother
define Heteroplasmy
multiple copies of mtDNA in each cell
