|
Hereditary sensory and autonomic neuropathy type I (HSAN I) or hereditary sensory neuropathy type I (HSN I) is a group of autosomal dominant inherited neurological diseases that affect the peripheral nervous system particularly on the sensory and autonomic functions. The hallmark of the disease is the marked loss of pain and temperature sensation in the distal parts of the lower limbs. The autonomic disturbances, if present, manifest as sweating abnormalities. The beginning of the disease varies between adolescence and adulthood. Since affected individuals cannot feel pain, minor wounds or blisters in the painless area may not be immediately recognized and can develop into extensive and deep foot ulcerations. Once infection occurs, the complications such as inflammation and progressive destruction of the underlying bones may follow and may require amputation of the surrounding area.〔〔 HSAN I is the most common type among the five types of HSAN. As a heterogeneous group of diseases, HSAN I can be divided into five subtypes HSAN IA-E. Most of the genes associated with the diseases have been identified. However, the molecular pathways leading to the manifestation of the diseases are not fully understood. Therefore, the potential targets for therapeutic interventions are not known. Moreover, gene-based therapies for patients with the diseases are not available to date, hence supportive care is the only treatment available for the patients.〔 == History == The first description of sporadic and familial cases of a condition that is compatible with HSAN was made in French literature in the 19th century. The main feature of the familial case was ulcers at the sole of the feet. In 1922, Hicks described a similar condition in a London family in which 10 persons suffered from perforating ulcers on their feet, lancinating and shooting pains, and deafness. Subsequently, Jughenn et al. and Denny-Brown demonstrated that the pathological process underlying the clinical features seen in these conditions was a neuropathy, rather than an anatomical disorder as had been previously suggested. Since then, many other familial conditions with similar clinical features have been reported.〔 The early names of the inherited neuropathies were given after the most prominent features or the suggested underlying mechanism of the diseases, such as ''mal perforant du pied'', ulcero-mutilating neuropathy, hereditary perforating ulcers, familial trophoneurosis, familial syringomyelia, hereditary sensory radicular neuropathy, among others. In dermatological literature, the term Thèvenard syndrome is still used for familial forms, whereas Bureau-Barrière syndrome is for sporadic forms. In 1975, Dyck and Otha proposed a descriptive classification of the diseases and introduced the term hereditary sensory neuropathy (HSN) which later was changed to hereditary sensory and autonomic neuropathy (HSAN) given the substantial autonomic involvement in the diseases.〔 The diseases were categorized into five types HSAN I-V based on the mode of inheritance, the predominant clinical features, and the age at onset. The diseases that are characterized by autosomal dominant mode of inheritance and adolescence or adulthood disease onset are categorized in HSAN I.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hereditary sensory and autonomic neuropathy type I」の詳細全文を読む スポンサード リンク
|