Ethidium Bromide stained polyacrylamide gels of PCR amplified products encompassing heteroplasmic variants G4812C, A4136G, A9194G, A10149T and T11916A analyzed by PCR-RFLP in patients and their respective mothers.

<p>Mutation G4812C causes a loss of <i>Dde I</i> site and hence shows a single band after digestion whereas wild type fragment shows 2 bands (bp). Variant A4136G creates an <i>Nla III</i> site and after digestion results in two bands of 43 bp and 107 bp. The heteroplasmic mutation has three bands (43 bp, 107 bp and 150 bp) as shown. Similarly other variants e.g. A9194G (creates <i>Hha I</i> site), A10149T (creates <i>Dde I</i> site) and T11916A (creates <i>Rsa I</i> site) and all result in 3 bands after digestion and separation on 12% PAGE. The homoplasmic mutations should yield only 2 bands lacking the wildtype band after separation on PAGE.