Inheritance of Disorders Caused by Mutations in the Mitochondrial Genome


Figure 7-24 Pedigree of Leber hereditary optic neuropathy, a form of adult-onset blindness caused by a defect in mitochondrial DNA. Inheritance is only through the maternal lineage, in agreement with the known maternal inheritance of mitochondrial DNA. Note that no affected male transmits the disease.




Replicative Segregation




Homoplasmy and Heteroplasmy



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Figure 7-25 Replicative segregation of a heteroplasmic mitochondrial mutation. Random partitioning of mutant and wild-type mitochondria through multiple rounds of mitosis produces a collection of daughter cells with wide variation in the proportion of mutant and wild-type mitochondria carried by each cell. Cell and tissue dysfunction results when the fraction of mitochondria that are carrying a mutation exceeds a threshold level. mtDNA, Mitochondrial DNA; N, nucleus.

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Nov 27, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Inheritance of Disorders Caused by Mutations in the Mitochondrial Genome
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