Reduction in size of the myotonic dystrophy trinucleotide repeat mutation during transmission

See allHide authors and affiliations

Science  05 Feb 1993:
Vol. 259, Issue 5096, pp. 809-812
DOI: 10.1126/science.8094260


Myotonic dystrophy (DM) is an autosomal-dominant disorder that affects 1 in 8000 individuals. Amplification of an unstable trinucleotide CTG repeat, located within the 3' untranslated region of a gene, correlates with a more severe DM phenotype. In three cases, the number of CTG repeats was reduced during the transmission of the DM allele; in one of these cases, the number was reduced to within the normal range and correlated at least with a delay in the onset of clinical signs of DM. Haplotype data of six polymorphic markers in the DM gene region indicate that, in this latter case, two stretches of the affected chromosome had been exchanged with that region of the wild-type chromosome.

Stay Connected to Science