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.
There are a number of causes of frameshift mutations. A common one happens when cells are exposed to UV rays from the sun. When a cell is hit with UV rays any sections of DNA that have a pair of Tâs side by side will cause these nucleotides to bond to each other rather than to the pair of Aâs on the opposite strand.