lecture 24 - human genome & disease Flashcards
What is the name for mutations that have been inherited and can therefore be passed on to offspring?
Germline mutations
What are somatic mutations?
Mutations to DNA in somatic cells, meaning they cannot be inherited
What is the name for a mutation that causes a gene to function poorly?
Loss of function mutation
Are loss of function mutations typically recessive or dominant, and why?
Recessive - if a normal copy of the gene exists on the homologous chromosome pair, then it can perform the genes intended function instead, meaning the mutation has no effect.
What is the name for a mutation that causes a gene to work ‘too well’?
Gain of function mutation
Are gain of function mutations typically dominant or recessive, and why?
Dominant - an allele that works too well will exceed the smaller effects of the normal allele.
What are monogenic diseases?
Disease caused by genetic mutations in single genes, that can be passed down generations
What is haemophilia?
A disorder of blood clotting
Are males or females more commonly affected by haemophilia?
Males
What mode of inheritance does Haemophilia display?
X linked recessive
What is the chance of a male inheriting Haemophilia (X linked recessive) if their mother is a carrier?
50%
Are males or females carriers of Haemophilia, an X linked recessive disorder?
Females - mutation on X chromosome so all males with mutation will be affected, not just carriers
What mode of inheritance is displayed by Huntington disease?
Autosomal dominant
Where is the mutated Huntingtin gene, that causes Huntington’s disease, found?
Chromosome 4
What is the mutation to the Huntingtin gene that causes Huntington’s disease?
Too many copies of the CAG triplet in the gene.