1. ¹Department of Biosciences and Nutrition, Karolinska Institutet, Karolinska University Hospital, Huddinge, Novum, Stockholm, Sweden
2. ²Department of Neuroscience, University of Pisa, Pisa, Italy

Correspondence: Dr M Eriksson, Department of Biosciences and Nutrition, Karolinska Institutet, Karolinska University Hospital, Huddinge, Novum, Stockholm SE-14186, Sweden. Tel: +46 858 583 731; Fax: +46 871 166 59; E-mail: Maria.Eriksson.2@ki.se

Received 10 September 2008; Revised 11 December 2008; Accepted 16 December 2008; Published online 28 January 2009.

Abstract

Most cases of the segmental progeroid syndrome, Hutchinson–Gilford progeria syndrome (HGPS), are caused by a de novo dominant mutation within a single codon of the LMNA gene. This mutation leads to the increased usage of an internal splice site that generates an alternative lamin A transcript with an internal deletion of 150 nucleotides, called lamin A150. The LMNA gene encodes two major proteins of the inner nuclear lamina, lamins A and C, but not much is known about their expression levels. Determination of the overall expression levels of the LMNA gene transcripts is an important step to further the understanding of the HGPS. In this study, we have performed absolute quantification of the lamins A, C and A150 transcripts in primary dermal fibroblasts from HGPS patients and unaffected age-matched and parent controls. We show that the lamin A150 transcript is present in unaffected controls but its expression is >160-fold lower than that in samples from HGPS patients. Analysis of transcript expression during in vitro aging shows that although the levels of lamin A and lamin C transcripts remain unchanged, the lamin A150 transcript increases in late passage cells from HGPS patients and parental controls. This study provides a new method for LMNA transcript analysis and insights into the expression of the LMNA gene in HGPS and normal cells.