Through statistics, it is suspected that one-half of cases are inherited, and one-half are the result of new,  de novo mutations. Cause loss of hearing
The hearing loss caused by NF2 is gradual and results from the presences of bilateral cochleovestibular schwannomas, also known as acoustic neuromas, which damage to cochlear nerve causing hearing loss. Hearing loss may also result from benign tumors that grow on the vestibular and auditory nerves, which lead to the inner ear. Pathogenesis
NF2 is caused by a defect in the gene that normally gives rise to a product called Merlin or Schwannomin, located on chromosome 22 band q11-13.1. Merlin was first discovered as a structural protein functioning as an actin cytoskeleton regulator. Later merlins tumour suppressant role was described. Merlin regulates multiple proliferative signalling cascades such as receptor tyrosine kinase signalling, p21-activated kinase signalling, Ras signalling, MEK-ERK cascade, MST-YAP cascade. In a normal cell, the concentrations of active (dephosphorylated) merlin are controlled by processes such as cell adhesion (which would indicate the need to restrain cell division). It has been shown that Merlin inhibits Rac1 which is crucial for cell motility and tumour invasion. Also, merlins interaction with cyclin D was described. It is known that Merlins deficiency can result in unmediated progression through the cell cycle due to the lack of contact-mediated tumour suppression, mainly because of the cell:cell junction disruption, sufficient to result in the tumors characteristic of Neurofibromatosis type II.
Hyperesthesia is a condition that involves an abnormal increase in sensitivity to stimuli of the sense. Stimuli of the senses can include sound that one hears, foods that one tastes, textures that one feels, and so forth. Increased touch sensitivity is referred to as "tactile hyperesthesia", and increased sound sensitivity is called "auditory hyperesthesia". In the context of pain hyperaesthesia can refer to an increase in sensitivity where there is both allodynia and hyperalgesia.In psychology, Jeanne Siaud-Facchin uses the term by defining it as an "exacerbation des sens": 37  that characterizes gifted individuals: for them, the sensory information reaches the brain much faster than the average, and the information is processed in a significantly shorter time. Other animals
Feline hyperesthesia syndrome is an uncommon but recognized condition in cats, particularly Siamese, Burmese, Himalayan, and Abyssinian cats. It can affect cats of all ages, though it is most prevalent during maturity. Detection can be somewhat difficult as it is characterized by brief bursts of abnormal behavior, lasting around a minute or two. One of its symptoms is also found in dogs that have canine distemper disease (CD) caused by canine distemper virus (CDV). See also
Auditory processing disorder
Hyperacusis
Multisensory integration
Sensory overload
Sensory processing
Sensory processing disorder
Sensory processing sensitivity

References


== External links ==