Somatic mosaicism, germline expansions, germline reversions and intergenerational reductions in myotonic dystrophy males: Small pool PCR analyses

Monckton, D.G. , Wong, L.J.C., Ashizawa, T. and Caskey, C.T. (1995) Somatic mosaicism, germline expansions, germline reversions and intergenerational reductions in myotonic dystrophy males: Small pool PCR analyses. Human Molecular Genetics, 4(1), 1 -8.

Abstract

In order to characterize the dynamics of CTG repeat instability in somatic and germline tissue from myotonic dystrophy (DM) males we have used small pool polymerase chain reaction (PCR) in a detailed quantitative analysis of repeat length variation, We demonstrate that the heterogeneous smear of CTG repeats observed in DM patients using standard analyses is comprised of multiple unresolved bands that may be dissected into discrete length alleles derived from single cells using single molecule PCR techniques, Analysis of somatic tissues demonstrates a bias toward increasing allele length and a lower boundary below which variant alleles are rare, consistent with a highly directional expansion pathway in the soma, Two sperm samples show extensive variation end a size increase bias, concordant with the phenomenon of anticipation, In addition, sperm analysis shows that targe contractions, including reversions into the normal size range, are restricted to the germline, Detailed analysis of intergenerational 'reductions' paternally transmitted to two offspring suggests that some apparent reductions may be artifacts of somatic expansion in the parent, Our data indicate that in addition to germline variation, substantial somatic expansion can also contribute to the intergenerational differences usually observed in DM.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Monckton, Professor Darren
• Authors: Monckton, D.G., Wong, L.J.C., Ashizawa, T., and Caskey, C.T.
• Subjects: R Medicine > RC Internal medicine; Q Science > QH Natural history > QH426 Genetics
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Human Molecular Genetics
• ISSN: 0964-6906