What is a common feature of diseases caused by frameshift mutations?

Diseases caused by frameshift mutations often lead to severe disruption of protein function due to the nature of how these mutations affect the genetic code. A frameshift mutation occurs when nucleotides are inserted into or deleted from the DNA sequence in numbers that are not multiples of three. This shifts the reading frame of the mRNA during translation, which can change every amino acid encoded downstream of the mutation. As a result, the resulting protein is likely to be truncated or to have an entirely different amino acid sequence, often leading to loss of function or the production of a nonfunctional protein.

The severity of the disruption depends on the specific mutation and its location within the gene, but it is common for frameshift mutations to lead to significant changes in the structure and function of proteins. This is particularly impactful in genes that are critical for normal cellular functions.