Burn J, Povey S, Boyd Y, Munro E A, West L, Harper K, Thomas D
J Med Genet. 1986 Dec;23(6):494-500. doi: 10.1136/jmg.23.6.494.
Monozygotic twin girls are reported, one of whom has the typical clinical features of Duchenne muscular dystrophy despite a normal female karyotype. Although certain features of the biopsy were atypical, the clinical diagnosis was supported by persistent markedly raised blood creatine kinase levels and findings typical of DMD on electromyography and magnetic resonance spectroscopy. Analysis of an X linked DNA polymorphism in 16 independent somatic cell hybrids made between cells derived from each girl and a mouse line suggest that in one twin only the maternal X chromosome is active, whereas in the other the active X was paternally derived. More data are needed to exclude sampling error. These preliminary experimental results support the hypothesis that both girls are heterozygous for Duchenne muscular dystrophy. X inactivation, by chance, resulted in two contrasting cell masses with different active X chromosomes. This segregation was followed by, and may even have resulted in, twinning into a female pair, one normal and one with the full clinical features of the disease.
据报道，有一对单卵双胞胎女孩，其中一个尽管核型为正常女性，但却具有杜氏肌营养不良症的典型临床特征。尽管活检的某些特征不典型，但持续显著升高的血液肌酸激酶水平以及肌电图和磁共振波谱显示的杜氏肌营养不良症典型表现支持了临床诊断。对来自每个女孩的细胞与一个小鼠品系构建的16个独立体细胞杂种中的X连锁DNA多态性进行分析表明，在一个双胞胎中只有母源X染色体是活跃的，而在另一个中活跃X染色体是父源的。需要更多数据来排除抽样误差。这些初步实验结果支持了这两个女孩都是杜氏肌营养不良症杂合子的假说。偶然的X染色体失活导致了具有不同活跃X染色体的两个对比性细胞群体。这种分离随后发生，甚至可能导致双胞胎发育成一对女性，一个正常，一个具有该疾病的全部临床特征。
