A dysfunctional Eustachian tube that is always open is called a patulous Eustachian tube. Patients with this rare condition are plagued by chronic ear infections. A much more common problem is a failure of the Eustachian tube to effectively regulate air pressure.
A frameshift mutation (also called a framing error or a reading frame shift) is a genetic mutation caused by indels (insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three.he frameshift mutation will also alter the first stop codon (UAA, UGA or UAG) encountered in the sequence. The polypeptide being created could be abnormally short or abnormally long, and will most likely not be functional.
Frameshift mutation (illustration). This type of mutation occurs when the addition or loss of DNA bases changes a geneâs reading frame. A reading frame consists of groups of 3 bases that each code for one amino acid.A frameshift mutation shifts the grouping of these bases and changes the code for amino acids. nonsense mutation is also a change in one DNA base pair. Instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. This type of mutation results in a shortened protein that may function improperly or not at all.