SNP Shot: Genomic Insights

Small fiber neuropathy is a disorder marked by intense pain episodes that usually start in the hands or feet. As individuals age, these pain attacks may spread to other parts of the body. Some individuals may initially experience widespread pain throughout their entire body. The pain is often described as stabbing, burning, or accompanied by unusual skin sensations like tingling or itching. The pain may intensify during periods of rest or at night for certain individuals. Typically, the symptoms of small fiber neuropathy emerge between adolescence and mid-adulthood.

People with small fiber neuropathy have difficulty feeling localized pain, such as the sensation of a pinprick. Conversely, they exhibit an elevated sensitivity to pain (hyperalgesia) and experience pain from stimuli that are normally painless (allodynia). Those affected may also struggle to distinguish between hot and cold temperatures. However, in some cases, cold or warm temperatures can trigger pain attacks.

Certain individuals with small fiber neuropathy may experience urinary or bowel dysfunction, rapid heartbeats (palpitations), dry eyes or mouth, or abnormal sweating patterns. They might also suffer from orthostatic hypotension, a sudden drop in blood pressure upon standing, potentially leading to dizziness, blurred vision, or fainting.

Small fiber neuropathy falls under the category of peripheral neuropathy, as it affects the peripheral nervous system. This system serves as a communication network between the brain and spinal cord and muscles and sensory cells that detect sensations like touch, smell, and pain.

Inheritance:

Small fiber neuropathy often follows an autosomal dominant inheritance pattern. This means that possessing only one copy of a mutated SCN9A or SCN10A gene within each cell is enough to trigger the condition. In some instances, the mutation is inherited from an affected parent. However, other cases arise from new gene mutations and occur in individuals with no prior family history of the disorder. When the underlying genetic cause remains unknown, or if small fiber neuropathy is triggered by another condition, the inheritance pattern cannot be clearly defined.