Hereditary sensory and autonomic neuropathy type IX with developmental delay (HSAN9)
OMIM number: 615031
Comments closing date: 12/11/2026
Hereditary sensory and autonomic neuropathy type IX with developmental delay (HSAN9) is a hereditary (genetic) condition affecting the development and function of the nervous system. The condition is primarily associated with developmental delay, learning difficulties, muscle weakness and stiffness, and breathing, swallowing and digestive problems from infancy. The condition is caused by a pathogenic variant in both copies of gene called TECPR2. This gene produces a protein which is important for the recycling and break-down of waste material in cells. These waste-products can build-up and damage nerve cells in individuals with HSAN9, which causes the features of the condition. People born with this condition can have variable features, but unfortunately, the condition is expected to significantly affect the quality of life from infancy, and life expectancy. There is no cure for this condition— treatment is primarily supportive care.
