Clinical trials are in progress for other drugs such as everolimus, lapatinib and mifepristone. Common aspirin has been studied as a low-risk therapeutic option. To date, there is no fully efficacious medical therapy for VS. The complexity of the molecular biology research involved is truly challenging. The development of a new generation of drugs may become a secondary therapy in view of advances in genome editing during the 1990s that led to the invention of CRISPR in 2009. CRISPR has become the preferred genome editing tool whereby diseases may be treated by correcting causative mutations directly in a patients genome. Observation of Small VS
The 1991 NIH Consensus Statement observed: "There is evidence that some patients with unilateral vestibular schwannoma and a subgroup of patients with NF2 may have tumors that fail to progress rapidly, resulting in stable neurologic function for a long time. The use of MRI with contrast enhancement has resulted in the identification of patients with very small, relatively asymptomatic vestibular schwannomas for whom the natural history is unknown. Conservative management may be appropriate for these patients." At the time, conservative management (i.e., observation, wait-and-watch/wait-and-scan) was reserved mainly for elderly or infirm patients. Data on tumor sizes at diagnosis and tumor growth behavior was sparse or contradictory and mainly short-term. The Central Brain Tumor Registry of the U.S., established in 1992, only began to keep records for benign tumors like VS in 2004.
As about the people with one copy of the H63D alteration (heterozygous carriers), this genotype is very unlikely to cause a clinical presentation, there is no predictable risk of iron overload. Besides that, two 2020 studies revealed that the frequency of homozygous or heterozygous H63D variant is significantly higher in elite endurance athletes comparing to ethnically matched controls, and is associated with high V̇O2max in male athletes. . Each patient with the susceptible genotype accumulates iron at different rates depending on iron intake, the exact nature of the genetic variant, and the presence of other insults to the liver, such as alcohol and viral disease. As such, the degree to which the liver and other organs are affected is highly variable and is dependent on these factors and co-morbidities, as well as age at which they are studied for manifestations of disease. Penetrance differs between populations. Disease-causing genetic variants of the HFE gene account for 90% of the cases of non-transfusion iron overload.This gene is closely linked to the HLA-A3 locus. Pathophysiology
Since the regulation of iron metabolism is still poorly understood, a clear model of how haemochromatosis operates is still not available. A working model describes the defect in the HFE gene, where a mutation puts the intestinal absorption of iron into overdrive. Normally, HFE facilitates the binding of transferrin, which is irons carrier protein in the blood. Transferrin levels are typically elevated at times of iron depletion (low ferritin stimulates the release of transferrin from the liver).