What is the type of mutation that causes bloom's syndrome?
This mutation deletes six DNA building blocks (nucleotides) and
replaces them with seven others at position 2281. The blmAsh
mutation results in the production of an abnormally short,
nonfunctional version of the BLM protein. This called a missense
The mutation is recessive and both parents must carry it to produce a child with the disorder. It is found in populations where there are close relatives that marry.
Other BLM gene mutations change single protein building blocks (amino acids) in the protein sequence or create a premature stop signal in the instructions for making the protein.
Duchenne muscular dystrophy is caused by a nonsence mutation in the dystrophin gene on the x-chromosome, this type mutation that occuurs in duchenne is what sets it apart from beckers or any other dystrophy. a nonsence mutation is a point mutation(additon or sutraction of a nucleotide in an exon) which causes the gene for dystrophin to be read half way which in turn causes muscle wasting.
By the nature of Down syndrome, which is a mutation of an extra (3rd) chromosome, more than one type of the same autologous gene is active: In homeostasis, only one type of each gene is active, but as the third chromosome does not get turned off in Down syndrome, two of the same type of gene are active.
The type of mutation that causes a defect in the gene (causing sickle cell anaemia) is a substitution mutation. A single nucleotide substitution (A to T) in the β-globin gene causes the amino acid valine to replace glutamic acid. This changes the resulting protein, causing a haemoglobin with an abnormal shape to be created.
Marfan syndrome is an autosomal dominant condition caused by a genetic mutation. The mutation occurs on chromosome 15 and affects the gene that encodes a protein called fibrillin-1. Over 100 mutations have been described, all of which impair the function of fibrillin-1. The precise reasons for the mutations are unknown. How the mutation manifests as the Marfan syndrome is also uncertain. There is mounting evidence that the fibrillin-1 defect allows for unabated activity of transforming…