Tg(DMWD,DMPK*,SIX5)328Ggo

This transgene consists of a 45 kb human genomic sequence extracted from lymphobalstoid cells from a patient with mild mytonic dystrophy. The 45 kb genomic sequence carries the DMWD, DMPK and SIX5 (DMAHP) genes. A part of the DMPK gene was replaced with a sequence extracted from a patient with severe mytonic dystrophy containing approximately 360 CTG repeats. Intergenerational instability of CTG size is seen, with the majority of descendants showing expansion of +1 to +60 CTG in one generation. A greater amplification in CTG repeats is seen after paternal transmission (by a mean of +20 CTG) than after maternal transmission (mean of +9 CTG) and even larger expansions of several hundred repeats (even 1000+) have been seen in subsequent generations. (J:168896)