Cutis laxa: reduced elastin gene expression in skin fibroblast cultures as determined by hybridizations with a homologous cDNA and an exon 1-specific oligonucleotide.

Fibroblast cultures were established from six patients with cutis laxa, and elastin gene expression was analyzed by RNA hybridizations with a 2.5-kilobase human elastin cDNA or an exon 1-specific 35-base oligomer. Northern analyses using either probe detected mRNA transcripts of approximately 3.5 kilobases, and no qualitative difference between the control and cutis laxa mRNAs was detected. However, quantitation of the elastin mRNA abundance by slot blot hybridizations revealed markedly reduced levels in all cutis laxa cell strains. Assuming equal translational activity of the control and cutis laxa mRNAs, the reduced mRNA levels could result in diminished elastin production, providing an explanation for the paucity of elastic fibers in the skin and other tissues in cutis laxa.