How would a change in the sequence of nucleotides in a dna molecule affect the mrna transcribed from the dna molecule?

There are several types of changes that could happen. If one of the letters of DNA were to be changed to a differnt letter, this might result in a differnt amino acid being put into the protein being synthesized. Or, changing a single letter could tell the protein to stop being made (a stop codon is formed) this would make a much smaller version of the protein. If a letter is either inserted or deleted this is called a "frame shift" mutation and this totally destroyes the message. A sudden change in the sequence of DNA could also "silence" the gene turning off transcription so that no mRNA would even be made. Or, it could enhance transcription increasing the ammount of mRNA. There are many many ways that a DNA mutation can affect mRNA, do you need anything more specific?Its very simple,mRNA is kinda messenger which takes information from genetic material(DNA) which will later get translated to functional protein.The information in genetic material is in the shape of sequence of nucleotides pairs.there are four kinda nucleotides 1.adenine,2.guanine3.cytosine4.thiamine nucleotides lare kinda codes which get imprinted on mRNA , where thiamine is exception coz it get transcribed to uracil.
,since mRNA does contain thiamine but it has a replacement known as uracil.So its very simple if there will be any change in nucleotide the information given to mRNA will also change .So u see sudden change in nucleotides will mean that information send to mRNA will get changed.other things getting affected would be protein..As mRNA will later translate this information to make proteins from amino acids