PT  - JOURNAL ARTICLE
AU  - J Burn
AU  - S Povey
AU  - Y Boyd
AU  - E A Munro
AU  - L West
AU  - K Harper
AU  - D Thomas
TI  - Duchenne muscular dystrophy in one of monozygotic twin girls.
AID  - 10.1136/jmg.23.6.494
DP  - 1986 Dec 01
TA  - Journal of Medical Genetics
PG  - 494--500
VI  - 23
IP  - 6
4099  - http://jmg.bmj.com/content/23/6/494.short
4100  - http://jmg.bmj.com/content/23/6/494.full
SO  - J Med Genet1986 Dec 01; 23
AB  - 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.