Epidemiology
Around 80 cases have been reported in the literature worldwide, hence this condition appears to be relatively rare. More than likely, sitosterolemia is significantly underdiagnosed and many patients are probably misdiagnosed with hyperlipidemia. See also
ABCG5 and ABCG8 Genes
Cerebrotendinous xanthomatosis

Notes
References
Lee M, Lu K, Patel SB (2001). "Genetic basis of sitosterolemia". Current Opinion in Lipidology. 12 (2): 141–149. doi:10.1097/00041433-200104000-00007. PMC 1350992. PMID 11264985. Steiner R D.  Sitosterolemia . [online] Available from : http://www.emedicine.com/ped/topic2110.htm [Accessed :12 July 2006]
Bazerbachi F.;  et al. (2017). "Cryptogenic Cirrhosis and Sitosterolemia: A Treatable Disease If Identified but Fatal If Missed". Annals of Hepatology. 16 (6): 970–978. doi:10.5604/01.3001.0010.5290. PMID 29055934. == External links ==
There are different forms of radiation therapy, including 3D conformal radiation therapy, intensity-modulated radiation therapy, particle beam therapy and brachytherapy, which are commonly used in the treatments of cancers of the head and neck. The expression of EBV latent proteins within undifferentiated nasopharyngeal carcinoma can be potentially exploited for immune-based therapies. Generally, there are three different types or treatment methods that can be used for patients with nasopharyngeal carcinoma. These three treatments are radiation therapy, chemotherapy, and surgery. Although there are currently three treatment methods, there are clinical trials taking place that may develop more effective treatments for NPC. A clinical trial is research study that works to develop new treatment techniques or to gain more information about or improve current methods. If an effective treatment comes out of the clinical trial, then this method may become a new standard treatment method. During the course of, or following, treatment, tests may be done in order to determine if the treatment is working, or if treatment needs to be dropped or changed. Tests that are done after treatment to determine the condition of patient after completing treatment are called follow-up tests and tell the doctor if the patients condition has changed or if the cancer has come back. Radiation therapy
Radiation therapy uses high energy x-rays or other types of radiation aimed to prevent cancer cells from growing or kill them altogether. This kind of therapy can be administered to the patient externally or internally.