A splice site mutation is a genetic

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

 mutation

Mutation

In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

 that inserts or deletes

Genetic deletion

In genetics, a deletion is a mutation in which a part of a chromosome or a sequence of DNA is missing. Deletion is the loss of genetic material. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome...

 a number of nucleotides in the specific site at which splicing

Splicing (genetics)

In molecular biology and genetics, splicing is a modification of an RNA after transcription, in which introns are removed and exons are joined. This is needed for the typical eukaryotic messenger RNA before it can be used to produce a correct protein through translation...

 of an intron

Intron

An intron is any nucleotide sequence within a gene that is removed by RNA splicing to generate the final mature RNA product of a gene. The term intron refers to both the DNA sequence within a gene, and the corresponding sequence in RNA transcripts. Sequences that are joined together in the final...

 takes place during the processing of precursor messenger RNA into mature messenger RNA

Mature messenger RNA

Mature messenger RNA, often abbreviated as mature mRNA is a eukaryotic RNA transcript that has been spliced and processed and is ready for translation in the course of protein synthesis...

. The abolishment of the splicing site results in one or more introns remaining in mature mRNA and may lead to the production of aberrant protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s. Several genetic diseases may be the result of splice site mutations. For example, mutations that cause the incorrect splicing of β-globin

Globin

Globins are a related family of proteins, which are thought to share a common ancestor. These proteins all incorporate the globin fold, a series of eight alpha helical segments. Two prominent members of this family include myoglobin and hemoglobin, which both bind the heme prosthetic group...

 mRNA are responsible of some cases of β-thalassemia

Beta-thalassemia

Beta-thalassemias are a group of inherited blood disorders caused by reduced or absent synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated...

. Another Example is TTP

Thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura is a rare disorder of the blood-coagulation system, causing extensive microscopic thromboses to form in small blood vessels throughout the body...

 (thrombotic thrombocytopenic purpura). TTP is caused by deficiency of ADAMTS-13. A splice site mutation of ADAMTS-13 gene can therefore cause TTP.