Since it is known that approximately 1 in 500 people in the general population will develop a sporadic schwannoma and there are no reports of the occurrence of schwannoma in 22q11.2DS, we investigated whether whole-gene deletion of LZTR1 occurs in schwannomatosis and assessed the risk of schwannoma in 22q11.2DS. The gene discussed is LZTR1; the disease is schwannoma.