CALR

MedlinePlus Genetics provides information about 19p13.13 deletion syndrome

Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are called somatic mutations, are not inherited. Somatic mutations in the CALR gene in early blood-forming cells are associated with essential thrombocythemia, a disorder characterized by an increased number of platelets, the blood cells involved in normal blood clotting. The mutations associated with this condition remove or add small amounts of genetic material to a region of the CALR gene called exon 9. These genetic changes lead to production of an altered calreticulin protein with a different sequence of building blocks (amino acids) at one end. It is not clear how the alteration in calreticulin affects the protein's function or leads to the signs and symptoms of essential thrombocythemia.

Somatic mutations in exon 9 of the CALR gene are also associated with primary myelofibrosis, a condition in which bone marrow is replaced by scar tissue (fibrosis). The effect of the genetic changes on calreticulin function is unknown, and researchers are working to determine how the altered protein is involved in primary myelofibrosis.