Quantitative Sensory Testing in a Girl With Tangier Disease: A Case Report.

Tangier disease is a rare genetic disorder caused by a deficiency in the ABCA1 gene, resulting in impaired metabolism of high-density lipoprotein (HDL) cholesterol. This disorder affects multiple organs, including the nervous system, and presents with a range of neurological symptoms. The primary neurological manifestation is peripheral nerve dysfunction, characterized by numbness, tingling, and weakness in the extremities. Autonomic dysfunction may also occur, causing bowel and bladder abnormalities. Cholesterol accumulation in nerve tissues is believed to be responsible for these symptoms. Research has shown that patients with Tangier disease commonly exhibit electrophysiological characteristics indicative of large fiber neuropathy. Small fiber neuropathy, a condition involving damage to small, unmyelinated nerve fibers, is not typically considered a defining feature of the disease. However, diagnostic methods such as quantitative sensory studies, which could help detect small fiber neuropathy, are often overlooked in the literature. In many cases, the diagnostic approach to neuropathy halts when electrodiagnostic studies return normal results, often disregarding the possibility of an underlying small fiber neuropathy. This may contribute to the underrecognition of small fiber neuropathy in Tangier disease.