Congenital Insensitivity TO Pain: A Case Report

Abstract

Congenital insensitivity to pain or more scientifically Hereditary sensory and autonomic neuropathies (HSAN) is a rare genetic disorder which associates a sensory dysfunction with a varying degree of autonomic dysfunction. Due to the peripheral neuropathy, a decreased sensitivity or even complete anesthesia may be present resulting in, on the ophthalmological level, neurotrophic ulcers. We report the case of 2 sisters (JM and KM) presenting with HSAN with recurrent corneal ulcers. Unfortunately, genetic testing couldn’t be performed due to lack of means, but the clinical presentation and features were very favourable or even pathognomonic of this syndrome. The first cases or reported individuals presenting with congenital insensitivity to pain goes back to 1930’s. Five types of hereditary sensory and autonomic neuropathy have been identified according to age of onset of symptoms, clinical features and affected gene. HSAN type IV also known as congenital insensitivity to pain with anhidrosis (CIPA) is the second most common HSAN. It is caused by mutation in the NTRK1(Neurotrophic tyrosine kinase receptor type 1) (TRKA) gene located in chromosome 1 (1q21-q22). It is characterized by repetitive hyperthermic episodes in infancy, and mental retardation is usually present, as reported in our case. Clinical symptoms of pain insensitivity manifest as tongue, lip and fingers biting, and self-inflicted injuries. Congenital insensitivity to pain is a rare genetic syndrome characterized by an absence or an altered response to pain. Individuals with this syndrome can presented self-inflicted injuries and auto-mutilation leading in some cases to severe disabilities. Long-term visual prognosis in CIPA patients is not assessed and there’s an important lack of data regarding ocular manifestation of CIP syndrome.