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Facioscapulohumeral muscular dystrophy (FSHMD, FSHD or FSH), which was originally named Landouzy-Dejerine,〔(disease overview ), MDA, date accessed 6 March 2007〕 is a usually autosomal dominant inherited form of muscular dystrophy (MD) that initially affects the skeletal muscles of the face (facio), scapula (scapulo) and upper arms (humeral). FSHD is widely stated to be the third most common genetic disease of skeletal muscle; Orpha.net lists the prevalence as 4/100,000〔(Prevalence of rare diseases: Bibliographic data ), www.orpha.net, May 2014, Number 1, Orphanet Report Series〕 while a 2014 population-based study in the Netherlands reported a significantly higher prevalence of 12 in 100,000. Symptoms may develop in early childhood and are usually noticeable in the teenage years with 95% of affected individuals manifesting disease by age 20 years. A progressive skeletal muscle weakness usually develops in other areas of the body as well; often the weakness is asymmetrical. Life expectancy can be threatened by respiratory insufficiency and up to 20% of affected individuals become severely disabled requiring use of a wheel chair or mobility scooter. In a Dutch study approximately 1% of patients required (nocturnal or diurnal) ventilatory support. Non-muscular symptoms frequently associated with FSHD include subclinical sensorineural hearing loss and retinal telangiectasia. In more than 95% of known cases, the disease is associated with contraction of the D4Z4 repeat in the 4q35 subtelomeric region of Chromosome 4. Seminal research published in August 2010 now shows that a second mechanism is needed for FSHD, which for the first time provides a unifying theory for the underlying genetics of FSHD. The second mechanism was found to be a "toxic gain of function" of the DUX4 gene which is the first time in the history of genetic research that a "dead gene" has been found to "wake up" and cause disease. Building on the 2010 unified theory of FSHD, researchers in 2014 published the first proposed pathophysiology definition of the disease and four viable therapeutic targets for possible intervention points.〔 ==History== FSHD was first described in 1884 by French physicians Louis Landouzy and Joseph Dejerine. In their paper of 1886, Landouzy and Dejerine drew attention to the familial nature of the disorder and mentioned that four generations were affected in the kindred that they had investigated.〔(Landouzy-Dejerine syndrome ), whonamedit.com, date accessed March 11, 2007〕 Formal definition of FSHD's clinical features didn't occur until 1952 when a large Utah family with FSHD was studied. Beginning about 1980 an increasing interest in FSHD led to increased understanding of the great variability in the disease and a growing understanding of the genetic and pathophysiological complexities. By the late 1990s, researchers were finally beginning to understand the regions of Chromosome 4 associated with FSHD.〔(Impossible Things: Through the looking glass with FSH Dystrophy Researchers ), Margaret Wahl, MDA, Quest magazine, Vol 14, No 2, March–April 2007〕 Since the publication of the unifying theory in 2010, researchers continued to refine their understanding of DUX4. With increasing confidence in this work, researchers proposed the first a consensus view in 2014 of the pathophysiology of the disease and potential approaches to therapeutic intervention based on that model.〔 〕 A chronology of important milestones in the history of genetic research related to FSHD is included below in the Genetics section. Over the years, FSHD has, at various times, been referred to as: * Landouzy-Dejerine〔 * Landouzy-Dejerine syndrome〔 * Erb-Landouzy-Dejerine syndrome〔 * Landouzy-Dejerine dystrophy or atrophy〔 * faciohumeroscapular 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「Facioscapulohumeral muscular dystrophy」の詳細全文を読む スポンサード リンク
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