title: Progressive expansion of the myotonic dystrophy CTG repeat in asymptomatic individuals in three successive generations of a family.
abstract: We report a family in which expansion of CTG repeats was detected in asymptomatic carriers of the myotonic dystrophy allele in three successive generations. PCR-based analysis of the expanded CTG repeat revealed intergenerational amplification of the mutation. We show here that the myotonic dystrophy mutation may remain clinically silent, not only in the oldest generation of a family, but even among siblings and offspring of symptomatic cases. This may represent a mechanism for the maintenance of the myotonic dystrophy gene in the population.
authors.affiliation: Service of Neurology, University Hospital "Marqués de Valdecilla", Faculty of Medicine, 39008 Santander, SpainService of Immunology, University Hospital "Marqués de Valdecilla", Faculty of Medicine, 39008 Santander, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Combarros
authors.forename: J
authors.initials: J
authors.lastname: Paz
authors.forename: J
authors.initials: J
authors.lastname: Berciano
authors.forename: J L
authors.initials: JL
authors.lastname: Fernández-Luna