<s>[INST] <<SYS>> This is a medical question of type : genetic changes <</SYS>> What are the genetic changes related to Cohen syndrome ? [/INST] Mutations in the VPS13B gene (frequently called the COH1 gene) cause Cohen syndrome. The function of the protein produced from the VPS13B gene is unknown; however, researchers suggest it may be involved in sorting and transporting proteins inside the cell. Most mutations in the VPS13B gene are believed to prevent cells from producing a functional VPS13B protein. It is unclear how loss of functional VPS13B protein leads to the signs and symptoms of Cohen syndrome. </s>