MT-ND4L

A mutation in the MT-ND4L gene has been identified in several families with Leber hereditary optic neuropathy. This mutation, which can be written as T10663C or Val65Ala, changes a single protein building block (amino acid) in the NADH dehydrogenase 4L protein. Specifically, it replaces the amino acid valine with the amino acid alanine at protein position 65.

Researchers have not determined how a mutation in the MT-ND4L gene can lead to the vision loss characteristic of Leber hereditary optic neuropathy. This genetic change appears to disrupt the normal activity of complex I in the mitochondrial inner membrane, which may affect the production of ATP. It remains unclear, however, why the effects of this mutation are limited to the nerve that relays visual information from the eye to the brain (the optic nerve). Additional genetic and environmental factors probably contribute to the features of Leber hereditary optic neuropathy.

MedlinePlus Genetics provides information about Mitochondrial complex I deficiency