Hereditary sensory neuropathy type II

Hereditary Sensory Neuropathy Type II (HSN2) is a rare genetic disorder characterized by the impairment of sensory functions, particularly affecting the peripheral nerves. This condition is part of a group of disorders known as Hereditary Sensory and Autonomic Neuropathies (HSAN), which are distinguished by their impact on the sensory and autonomic nervous systems. HSN2 specifically involves a marked reduction in the ability to feel pain and temperature changes, leading to repeated injuries and wounds that the affected individual may not notice.

Causes

HSN2 is caused by mutations in the WSCD1 gene, which plays a crucial role in the development and function of peripheral sensory neurons. These mutations are inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to be affected by the disorder.

Symptoms

The primary symptoms of HSN2 include a reduced ability to feel pain and temperature, leading to an increased risk of burns, wounds, and infections, particularly on the hands and feet. Affected individuals may also experience chronic skin ulcers and, in some cases, bone infections or osteomyelitis. Due to the lack of protective sensations, minor injuries can lead to significant complications, including amputations in severe cases. Additionally, some individuals with HSN2 may exhibit muscle weakness and wasting, particularly in the lower limbs, as the disease progresses.

Diagnosis

Diagnosis of HSN2 is primarily based on clinical evaluation and the characteristic symptoms of the disease. Genetic testing can confirm the diagnosis by identifying mutations in the WSCD1 gene. Nerve conduction studies and electromyography (EMG) may also be used to assess the extent of nerve damage and to differentiate HSN2 from other forms of neuropathy.

Treatment

There is currently no cure for HSN2, and treatment focuses on managing symptoms and preventing complications. This may include regular monitoring and care of the skin and feet to prevent injuries and infections, the use of protective footwear, and pain management strategies. In some cases, surgery may be necessary to treat chronic ulcers or other complications. Physical therapy may also be beneficial to maintain muscle strength and mobility.

Prognosis

The prognosis for individuals with HSN2 varies depending on the severity of the symptoms and the effectiveness of management strategies. With appropriate care, many affected individuals can lead active lives, although they may face challenges related to their sensory impairments.