Congenital insensitivity to pain with anhidrosis

Hereditary sensory and autonomic neuropathy type IV, HSAN IV short, is an extremely rare genetic disease from the group of primary neuropathies. The disease was first described in 1963. In English-speaking hereditary sensory and autonomic neuropathy is also known by the acronym CIPA for " congenital insensitivity to pain and anhidrosis ". So far, less than 100 cases have been documented worldwide.

Clinic

In the English name of the main symptoms are called: the clinical picture is at birth a considerable disturbance of pain and temperature sense and a anhidrosis. Due to the disturbance of pain and temperature sense it comes to burns and injuries; also self-injurious behavior was described. The lack of perspiration thermoregulation is disrupted and it can lead to hyperthermia. The symptoms usually occur late in the first year of life, as does the CIPA syndrome in contrast to many other diseases not by pain, but by their absence felt. Therefore affected children do not complain of pain, but rather are perceived as quiet. Thus, the disease falls on only if the child does not respond to an obvious injury or hurt themselves. In addition, there may be significant, unexplained fever.

Diagnosis

On the basis of neuropathological tests or an analysis of the NTRK1 gene, the CIPA syndrome can be detected. An examination of the sweat glands is only helpful insofar as they are not innervated. The structure of the sweat glands, however, is unchanged.

Genetics

The inheritance path of the disease is heterogeneous, the syndrome is inherited as an autosomal recessive trait. Based in most cases, a mutation of the NTRK1 - gene coding for a tyrosine kinase receptor of the family of neurotrophin receptors. The gene plays an important role for the growth factor of certain neurons. This growth factor is a nerve growth factor (nerve growth factor, NGF ) is known. Thus, the gene is critically involved in the development and survival of the nozizeptorischen nervous system. As the sweat glands are innervated in nozizeptorischen nervous system, the NTRK1 gene also has implications for the regulation of body temperature by sweating. The disease is of great scientific interest because a substantial interest of the NTRK1 receptor can be derived in the development and function of pain perception and sweat regulation of this gene defect.