The hereditary sensory neuropathies (HSN) include 4-6 similar but distinct inherited degenerative disorders of the nervous system (neurodegenerative) that frequently progress to loss of feeling, especially in the hands and feet. Some types of HSN are related to or identical with some forms of Charcot-Marie-Tooth disorder, and others are related to or identical with familial dysautonomia (Riley-Day syndrome). The classification of the HSNs is complicated, and the experts do not always agree on it.
Hereditary sensory neuropathy type II (HSN2) is a rare genetic disorder that usually begins in childhood by affecting the nerves that serve the lower arms and hands and the lower legs and feet (the peripheral nerves). Symptoms start with inflamed fingers or toes especially around the nails. Infection is common and worsens as ulcers (open sores) form on the fingers and on the soles of the feet. The loss of sensation in both hands and feet often leads to neglect of the wounds. This can become serious, even leading to amputation in extreme cases, so it is important to care for any such wounds.
The disorder affects many of the body's systems, is characterized by early onset (infancy or early childhood) and is transmitted genetically as an autosomal recessive trait.