Figure 4. Molecular studies. A: Sequence chromatogram from a normal subject (top) and a CORD patient (bottom) with a homozygous insertion of T at position 1349 of the cDNA (c.1349insT) which results in a frame-shift starting at codon 452 and a putative stop codon 12 amino acids downstream in the translated protein (p.Y452fs12X). B: ABI 3100 assay for the detection of the PROM1 mutation. The 1bp difference is evident in the homozygotes (reading peak at 201 bp) compared to controls (reading peak at 200 bp). Heterozygotes appear as two peaks.