What is Leber's hereditary optic neuropathy (LHON)?
LHON causes a painless loss of central vision and usually occurs when someone with the condition is between 12 and 30 years old.
- Both eyes are affected at the same time.
- Males won’t pass the gene to any of their children
- Females with the mutation do pass it to all of their children
What is mitochondrial inheritance?
The normal 46 chromosomes in our body are contained in the center of the cell, which is called the nucleus. Mitochondria are structures in the cell that are located outside of the nucleus in the cytoplasm and also contain genes that are separate from the ones in the nucleus.
Unlike nuclear genes, which are inherited from both parents, mitochondrial genes are inherited only from the mother. If there is a mutation in a mitochondrial gene, it’s passed from a mother to all of her children; sons won’t pass it on, but daughters will pass it on to all of their children.
The first human disease that was associated with a mutation in mitochondrial DNA is called Leber's Hereditary Optic Neuropathy, or LHON.