Heteroplasmic substitutions in the mitochondrial DNA control region in mother and child samples

The sequences of the two hypervariable regions of the mitochondrial DNA con trol region (HV1 and HV2) from close maternal relatives (mother-child pairs ) were compared to determine the frequency of mutations between two generat ions. A total of 68 blood samples were sequenced only in HV1 and 86 were an alysed for HV1 and HV2. The intergenerational comparison led to the identif ication of six heteroplasmic point mutations affecting the children only. I n one case a heteroplasmy of the maternal sequence was resolved to homoplas my in the corresponding sequence of the child.