Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-12-20
pubmed:abstractText
In 1990, Richards et al. reported dramatically skewed lyonization in a set of female monozygotic twins heterozygous for Duchenne muscular dystrophy (DMD). The skewed inactivation pattern was symmetrical in opposite directions, one twin being affected with DMD, the other one being normal. Here, we report an additional set of female monozygotic twins heterozygous for a mutation at the dystrophin locus. Similarly, one shows a manifesting carrier phenotype while one is normal. However, unlike the previous report, we find a skewed X inactivation pattern only in the affected twin, while the normal twin showed a random X inactivation pattern. Our results lend considerable experimental support for the models of twinning and X inactivation recently outlined by Nance in 1990, in that these twins probably represent asymmetric splitting of the inner cell mass (ICM): The affected twin likely arose when a small proportion of the ICM split off after lyonization had occurred. In this situation, the original ICM could give rise to the normal twin with random lyonization, while the newly split cells would experience catch-up growth and lead to the affected twin. Genetic studies of this family showed that the specific dystrophin gene mutation was an exon duplication that arose sporadically in the paternally derived X chromosome.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0148-7299
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
354-64
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:1683155-Adult, pubmed-meshheading:1683155-Blotting, Southern, pubmed-meshheading:1683155-Child, pubmed-meshheading:1683155-DNA, pubmed-meshheading:1683155-Densitometry, pubmed-meshheading:1683155-Diseases in Twins, pubmed-meshheading:1683155-Dosage Compensation, Genetic, pubmed-meshheading:1683155-Dystrophin, pubmed-meshheading:1683155-Female, pubmed-meshheading:1683155-Heterozygote Detection, pubmed-meshheading:1683155-Humans, pubmed-meshheading:1683155-Male, pubmed-meshheading:1683155-Methylation, pubmed-meshheading:1683155-Multigene Family, pubmed-meshheading:1683155-Muscles, pubmed-meshheading:1683155-Muscular Dystrophies, pubmed-meshheading:1683155-Mutation, pubmed-meshheading:1683155-Pedigree, pubmed-meshheading:1683155-Polymerase Chain Reaction, pubmed-meshheading:1683155-Polymorphism, Restriction Fragment Length, pubmed-meshheading:1683155-Twins, Monozygotic, pubmed-meshheading:1683155-X Chromosome
pubmed:year
1991
pubmed:articleTitle
Discordance of muscular dystrophy in monozygotic female twins: evidence supporting asymmetric splitting of the inner cell mass in a manifesting carrier of Duchenne dystrophy.
pubmed:affiliation
Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't