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Barth syndrome (BTHS), also known as 3-Methylglutaconic aciduria type II, is an X-linked genetic disorder. The disorder, which affects multiple body systems, is found exclusively in males. It is named after Dutch pediatric neurologist Peter Barth. ==Presentation== Though not always present, the cardinal characteristics of this multi-system disorder include: cardiomyopathy (dilated or hypertrophic, possibly with left ventricular noncompaction and/or endocardial fibroelastosis), neutropenia (chronic, cyclic, or intermittent),〔 underdeveloped skeletal musculature and muscle weakness, growth delay,〔 exercise intolerance, cardiolipin abnormalities, and 3-methylglutaconic aciduria.〔 It can be associated with stillbirth. Barth syndrome is manifested in a variety of ways at birth. A majority of BTHS patients are hypotonic at birth, show signs of cardiomyopathy within the first few months of life, and experience a deceleration in growth in the first year, despite adequate nutrition. As patients progress into childhood, their height and weight lag significantly behind other children. While most patients express normal intelligence, a high proportion of BTHS patients also express mild or moderate learning disabilities. Physical activity is also hindered due to diminished muscular development and muscular hypotonia. Many of these disorders are resolved after puberty. Growth accelerates during puberty, and many patients reach a normal adult height.〔Kelley RI, (6 Dec 2011 ). “Barth Syndrome - X-linked Cardiomyopathy and Neutropenia”. Department of Pediatrics, Johns Hopkins Medical Institutions. Available from: http://www.hopkinsmedicine.org/cmsl/Barth_Summary.html〕 Cardiomyopathy is one of the more severe manifestations of BTHS. The myocardium is dilated, reducing the systolic pump of the ventricles. For this reason, most BTHS patients have left myocardial thickening (hypertrophy). While cardiomyopathy can be life-threatening, it is commonly resolved or substantially improved in BTHS patients after puberty.〔 Neutropenia is another deadly manifestation of BTHS. Neutropenia is a granulocyte disorder that results in a low production of neutrophils, the body’s primary defenders against bacterial infections. Surprisingly, however, BTHS patients have relatively fewer bacterial infections than other patients with neutropenia.〔Barth Syndrome Foundation, 28 Jun 2011. “Diagnosis of Barth Syndrome”. Available from: http://barthsyndrome.org/english/view.asp?x=1435&mid=424〕 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「Barth syndrome」の詳細全文を読む スポンサード リンク
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