Figure 3.

Effect of the COL1A1 polymorphism on allele-specific transcription in heterozygotes. (a) Position of the primers designed to detect the polymorphic site at position 1240 in the first intron of the human COL1A1 gene (Sequence Accession number M20789). (b) Representative electropherograms from GeneScan analysis of RFLP-PCR assays from one patient. Equivalent amounts of genomic DNA (gDNA; top), cDNA (middle), and non–reverse-transcribed RNA (bottom) were used as PCR template. The increased abundance of “s” allele–derived transcripts is reflected by the greater area under the curve of the “s”-derived PCR products on RFLP-PCR analysis of cDNA. (c) Mean ± SEM ratios of product abundance derived from the “s” and “S” alleles for gDNA. Ratios were measured in duplicate samples of gDNA and cDNA from ten patients.