possible by chorionic villus sampling or amniocentesis. Treatments Treatment remains largely supportive. The behavioral disturbances of MPS-III respond poorly to medication. If an early diagnosis is made, bone marrow replacement may be beneficial. Although the missing enzyme can be manufactured and given intravenously, it cannot penetrate the blood–brain barrier and therefore cannot treat the neurological manifestations of the disease. Along with many other lysosomal storage diseases, MPS-III exists as a model of a monogenetic disease involving the central nervous system. Several promising therapies are in development. The French company Lysogene is conducting a phase II/III clinical trial of a gene therapy-based treatment. Other potential therapies include chemical modification of deficient enzymes to allow them to penetrate the blood–brain barrier, stabilisation of abnormal but active enzyme to prevent its degradation, and implantation of stem cells strongly expressing the missing enzyme. For any future treatment to be successful, it must be administered as early as possible. Currently MPS-III is mainly diagnosed clinically, by which stage it is probably too late for any treatment to be very effective. Neonatal screening programs would provide the earliest possible diagnosis. The flavonoid genistein decreases the accumulation of GAGs. In vitro, animal studies and clinical experiments suggest that the symptoms of the disease may be alleviated by an adequate dose of genistein. Despite its reported beneficial properties, genistein also has toxic side effects. Several support and research groups have been established to speed the development of new treatments for Sanfilippo syndrome. Participants in the first-ever "Caregiver Preference Study for Sanfilippo Syndrome" advocated for clinical trials that shift focus from primary cognitive outcomes to other multisystem endpoints, and perceptions of non-curative therapies revealed a preference for treatment options that stop or slow the disorder progression to maintain the child’s current function to ensure quality of life; thus, parents express high risk tolerance and a desire for broader inclusion criteria for trials. Prognosis According to a study of patients with Sanfilippo syndrome, the median life expectancy varies depending on the subtype. In Sanfilippo syndrome type A, the mean age at death (± standard deviation) was 15.22 ± 4.22 years. For type B, it was 18.91 ± 7.33 years, and for type C it was 23.43 ± 9.47 years. The mean life expectancy for type A has increased since the 1970s. Epidemiology Incidence of Sanfilippo syndrome varies geographically, with approximately 1 case per 280,000 live births in Northern Ireland, 1