Kinoshita M, Ikeda K, Yoshimura M, Saku A, Watanabe K
Fourth Department of Internal Medicine, Toho University.
Rinsho Shinkeigaku. 1990 Jun;30(6):643-6.
A 53-year-old female with muscular symptoms and incomplete Turner's syndrome was presented. She had two sons with Duchenne type muscular dystrophy (DMD). Her muscular symptoms became apparent at age 52 years, and her elevated serum CK, EMG and pathological findings of the biopsied muscle were consistent with muscular dystrophy. Her cytogenetic analysis from the cultured lymphocytes and fibroblasts showed a 45XO/46XX/47XXX chromosome constitution. Analysis of number of Barr bodies in the muscle specimen revealed that the total number of the bodies were significantly decreased in this case than in the control muscles. The result indicated that nuclei of 45XO karyotype were evidently present in her muscle and contributed to the process of muscle fiber breakdown as a major pathogenetic factor. However, inactivation of normal X chromosome also concerned the pathologic process because there were nuclei with Barr bodies in the damaged fibers as well. Only seven cases with X chromosome mosaicism and muscular symptoms attributable to DMD gene were seen in the literature. Four of them showed rather typical clinical features of DMD, but the muscular symptoms were much milder in the remainder, and patients were still able to walk in their middle lives. It was presumed that the severity of the clinical symptoms was parallel to the ratio of 45XO karyotype in the total number of muscular nuclei.
报告了一名53岁患有肌肉症状和不完全特纳综合征的女性。她有两个患杜氏型肌营养不良症（DMD）的儿子。她的肌肉症状在52岁时变得明显，其血清肌酸激酶升高、肌电图以及活检肌肉的病理结果均与肌营养不良症相符。对培养的淋巴细胞和成纤维细胞进行的细胞遗传学分析显示其染色体组成为45,XO/46,XX/47,XXX。对肌肉标本中巴氏小体数量的分析表明，与对照肌肉相比，该病例中巴氏小体的总数显著减少。结果表明，45,XO核型的细胞核明显存在于她的肌肉中，并作为主要致病因素参与了肌纤维破坏过程。然而，正常X染色体的失活也与病理过程有关，因为在受损纤维中也存在带有巴氏小体的细胞核。文献中仅见7例具有X染色体嵌合且肌肉症状归因于DMD基因的病例。其中4例表现出相当典型的DMD临床特征，但其余病例的肌肉症状要轻得多，患者在中年时仍能行走。据推测，临床症状的严重程度与肌细胞核总数中45,XO核型的比例平行。
